hybridfree/eevblog-posts huggingface dataset:
Weird RF module - Page 1
Forum section: electronics / rf-microwave

author: EggertEnjoyer123
author_rank: Frequent Contributor
timestamp: May 12, 2024, 10:02:49 am
content: I bought this weird RF module for a couple dollars at a ham radio. (It is a MHL70031 from Anritsu).The device has 3 3.5mm connectors, and 24 feedthroughs. I opened up the device and took pictures using a microscope.It appears to be some sort of amplifier. Any idea on what the module is supposed to do? My uneducated guess is that it is some sort of comparator (since all the transistors seem to be in pairs, and at the input we seem to have a differential pair with one of the transistors connected to a voltage divider).

author: D Straney
author_rank: Frequent Contributor
timestamp: May 12, 2024, 07:01:20 pm
content: That is an absolutely wild mess of wirebonds from the DC pins. Interesting that it has 3 coax connections. I'd bet you could trace the full circuit if you wanted to since it's all visible there (if you can figure out the pinouts of the bare dies, that is). A high-speed "square-ifier" that turns an RF input into two complementary fixed-amplitude outputs sounds plausible as something that could be useful in certain test equipment.Also: wonder what's up with the two traces at the left edge that look like they're doing a narrow-to-wide transition for a coax connector, and then go nowhere? And the weird bridge over the right-hand coax connection, that has a resistor sitting on top of it?

author: EggertEnjoyer123
author_rank: Frequent Contributor
timestamp: May 12, 2024, 08:36:27 pm
content: Quote from: D Straney on May 12, 2024, 07:01:20 pmThe narrow to wide transitions are connected to the coax connectors. There's two coax connectors on the left and one on the right. The bridge thing contains an inductor for (presumably) DC biasing.I'm unsure what the transistors are, since I'm not well versed in wirebond components. Look like dual gate FETs?

author: D Straney
author_rank: Frequent Contributor
timestamp: May 13, 2024, 04:48:56 pm
content: Quote from: EggertEnjoyer123 on May 12, 2024, 08:36:27 pmI was thinking of the middle two actually (see photo).Dual-gate FET sounds plenty plausible, or dual FET on a single die. I couldn't find any die shots of dual-gate RF FETs, but Zeptobars has a few RF BJTs, which all have interleaved-finger structures that these ones don't have:https://zeptobars.com/en/read/Infineon-BFR740-42GHz-BJT-npnhttps://zeptobars.com/en/read/BFR93-bjt-bipolar-RF-npn-transistorhttps://zeptobars.com/en/read/Infineon-BFP450-linear-low-noise-BJT-Siemens-RF-24Ghz-fThttps://zeptobars.com/en/read/Infineon-BFP540FESD-30Ghz-fT-NPN-BJT-RF
Help me identify this RF Connector - Page 1
Forum section: electronics / rf-microwave

author: CrazyTiger
author_rank: Regular Contributor
timestamp: May 08, 2024, 07:26:21 am
content: Hi All,I am trying to find a replacement of connector assembly . At first glance, I thought its a common 7/16 connector to N male But this connector really looks odd. Please help me to identify this:Here is the a comparison with all other high power connectors I have at hand.Thanks

author: AndrewEp17
author_rank: Contributor
timestamp: May 09, 2024, 06:12:25 pm
content: Maybe it is custom made. What is it from?

author: Harry_22
author_rank: Frequent Contributor
timestamp: May 10, 2024, 02:23:09 pm
content: Hi! It looks like a side for cable assembling. Do you have a mating part?

author: ConKbot
author_rank: Super Contributor
timestamp: May 10, 2024, 03:37:12 pm
content: I'd agree it looks like a cable mount connection. Fingers on the inside of the center contact are to slip over the conductor without having to solder to it. (I've done 7/8 heliax, and soldering the center conductor to a contact involved a heat shield for the dielectric, and a torch.)With some sort of clamping/retention mechanism for the shield missing.

author: CrazyTiger
author_rank: Regular Contributor
timestamp: May 11, 2024, 06:05:05 am
content: This connector came attached together with a dismantled UHF antenna 225MHz to 400MHz. It was installed on a naval ship. The contractor who dismantled the antenna, must have had removed it on the wrong end instead of removing the N connector. Apparently the cable being used is corrugated type. Cable mount connection, makes sense. Let me see if I can get picture for the mating end.

author: ConKbot
author_rank: Super Contributor
timestamp: May 13, 2024, 02:22:47 am
content: https://www.commscope.com/product-type/connectors/wireless-transmission-connectors/wireless-radiating-connectors/iteml4nm-f/is an example of a similar style of connector. Since you mentioned a corrugated jacket, I'm assuming it's heliax, or similar.
Anritsu OSLN50-1 calibration Tee - need cal constants - Page 1
Forum section: electronics / rf-microwave

author: EE-digger
author_rank: Frequent Contributor
timestamp: May 10, 2024, 04:21:03 pm
content: Do you guys mind a little cross posting to Test Equipment? There are really two different groups of members.If not, does anyone have cal constants for this Anritsu Tee cal kit (OSL)? I've measured the delays but would like to get the Cx and Lx values correct for use to 6GHz. Anyone with a VNA Master or relative of it may be able to bring up the values, I don't know.
Passive RF SP12T Switch? Does it exist? Is there a better way? - Page 1
Forum section: electronics / rf-microwave

author: tbw2
author_rank: Contributor
timestamp: May 07, 2024, 10:09:37 am
content: How could I select between a dozen 5MHz@400Vpk-pk signals, passively, whilst maintaining good isolation, and 50Ohm Characteristic impedance?Currently I have a "cat of nine tails" cable which is slow and fragile.I am imagining a rotary switch with 12 poles, but cannot find a 50Ohm characteristic impedance version. Do they even exist?What other solutions are out there?Thank you in advance.

author: ejeffrey
author_rank: Super Contributor
timestamp: May 07, 2024, 03:26:37 pm
content: I would use coaxial relays. There are 6 pole and 2 pole versions widely available, you can cascade them to make 12.

author: tbw2
author_rank: Contributor
timestamp: May 08, 2024, 08:36:41 am
content: Quote from: ejeffrey on May 07, 2024, 03:26:37 pmThanks for the reply. I must be searching the wrong keywords because I am not seeing any 6 pole RF relays, apart from Digikey 3985-PE71S6486-ND which is $$$I may just have to make something up with a dozen individual relays on a PCB.

author: MartinL
author_rank: Regular Contributor
timestamp: May 08, 2024, 12:09:37 pm
content: A 400Vpk-pk sine wave in a 50 ohm system corresponds to 400W of RF power throughput. That's quite a lot. Those Pasternack coax relays are only rated to 20W input power.But at 5MHz you are in HF territory. You can look at amateur radio equipment for the HF bands for examples of how to do this. Generally, HF designs do not bother to try to maintain 50 ohm characteristic impedance through the relays. This is a reasonable choice because the relays are electrically extremely short (millimetres) compared to the wavelength (in this case 60 metres), so the effect of the short mismatched section is negligible.At 400Vpk-pk, the RMS voltage is 141V, and RMS current into a 50 ohm load is 2.82A, so you can use common off the shelf relays rated for 250V AC at 3A or more.

author: mtwieg
author_rank: Frequent Contributor
timestamp: May 08, 2024, 01:27:55 pm
content: I agree with MartinL, at 5MHz fancy "RF" relays are just a waste of money. Common relays used for mains applications should be fine. Many HAM radio builds make use of Omron relays for antenna tuners, bypasses, selectors, etc. Often into the kW power range (so long as there's no hot switching).

author: tbw2
author_rank: Contributor
timestamp: May 08, 2024, 03:17:56 pm
content: Thank you for the responses.

author: vk4ffab
author_rank: Frequent Contributor
timestamp: May 09, 2024, 11:03:40 pm
content: Quote from: tbw2 on May 08, 2024, 03:17:56 pmOmron G2RL series of relays are the goto for many ham homebrewers, Good for over 500W to 50Mhz. Depending on where you buy, a couple bucks a unit. Single and double pole only though.
Where are some good websites or videos to learn about faraday cages and basic RF - Page 1
Forum section: electronics / rf-microwave

author: AndrewEp17
author_rank: Contributor
timestamp: May 08, 2024, 05:18:20 pm
content: I'm building a Gu-81 tesla coil and i want to build a faraday cage around it, but any time i search on google for a anything related to a faraday cages i just get a bunch of conspiracy nuts making "tutorials" of them wrapping their phones in foil because they think their phone is mind controlling them or something. So where can i find good info on faraday cages and just RF stuff in general that isn't a bunch of conspiracy misinformation?

author: pdenisowski
author_rank: Super Contributor
timestamp: May 08, 2024, 05:29:26 pm
content: Quote from: AndrewEp17 on May 08, 2024, 05:18:20 pmNothing (yet!) on Faraday cages, but I've made quite a few videos on basic RF topicshttps://www.youtube.com/playlist?list=PLKxVoO5jUTlvsVtDcqrVn0ybqBVlLj2z8You might have better luck searching for "RF shielding" I work in RF and rarely hear the expression "Faraday cage" in a "work" environment - "shield room / box" or "screen room / box" is the more common term in my experience.
Are here some Hytera Radio Specialist? - Page 1
Forum section: electronics / rf-microwave

author: Lord of nothing
author_rank: Super Contributor
timestamp: May 20, 2024, 11:10:27 pm
content: HiLong story short I own some PD6 who support Variouse Services with an old but working Hytera "Demo" Software. One if them is Data Transfer between 2 Radios!Why is that important? Well since in an Emergency Case People should be able just with an Handheld Radio (in an Pouch) and an Tablet be able to access Data.The Radio support other thinks via the Cable to. Sadly I found no way to push Audio Digital from the Radio to the Tablet. Are there any ways or do I need to "Digitise" the Audio again? I found an Pinout but I am not sure if Pins are used for different function twice (like Voice and Data).Thanks!
Make break modulation, what is it? - Page 1
Forum section: electronics / rf-microwave

author: videobruce
author_rank: Frequent Contributor
timestamp: May 05, 2024, 08:27:22 am
content: Anyone have any idea what that is suppose to mean regarding a RF signal generator?Is it 'pulse' modulation they are talking about?https://www.ebay.com/itm/363093060221(see the details in the ad)

author: Andy Watson
author_rank: Super Contributor
timestamp: May 05, 2024, 09:57:35 am
content: I think you are correct. In the specifications it says:QuoteIt's on/off modulation, i.e. 100% pulse modulation.Check this thread:https://www.eevblog.com/forum/testgear/wb-sg1-wide-band-generator/msg2884174/#msg2884174There's a manuall lurking somewhere too.

author: videobruce
author_rank: Frequent Contributor
timestamp: May 05, 2024, 01:04:32 pm
content: Yep, that's it, same OSD , how can that be used as a constant signal source for adjusting/tweaking a receiver?
Keysight Genesys to Altium Designer - Page 1
Forum section: electronics / rf-microwave

author: sarason
author_rank: Contributor
timestamp: May 05, 2024, 01:47:02 am
content: Does anyone know of a tool or a plugin that works with Genesys to convert their schematic and pcb files to Altium Designer shematic and pcb files and vice versaAny other easy way to achieve this?sarason
Rohde & Schwarz SMS - Page 1
Forum section: electronics / rf-microwave

author: Repairman
author_rank: Newbie
timestamp: May 03, 2024, 10:39:18 am
content: I'm sure my topic has been discussed at length before but nowhere can I see a solution.My SMS signal generator arrived with a blown fuse and a bad on/off switchI recapped the PSU and fitted a new switch but found the display to be (still) garbled with keys unresponsive.I ended up blaming the (apparently dead) P8049 microprocessor but eventually found I could get its 6MHz oscillator running by adding 470 ohms from Pin 3 to 5 volts.I tested the display board on my working SMS2 and its fine.With the pull up resistor I can now see 6MHz at the crystal pins but no microprocessor activityWhen I fitted an unprogrammed P8742 (without the 470 ohm resistor) to test the oscillator circuit it was OK.I'm wondering if an on-board PSU on the P8049 chip has failed which prevented the oscillator running and killed the internal logic.I can't find a detailed schematic for a 8049 to see if it has an internal regulated supplyHas anyone got a solution?Allan
Feedline measurements - Page 1
Forum section: electronics / rf-microwave

author: dobsonr741
author_rank: Frequent Contributor
timestamp: May 10, 2024, 02:04:55 pm
content: I'm setting up a feed line from my office to the attic reusing existing RG6 segments. How can I measure reflections/loss/etc by hooking up to nano VNA, but having access to only one end at a time? I expect it to work from 20m to 2m only for QRP powers.

author: mag_therm
author_rank: Frequent Contributor
timestamp: May 10, 2024, 03:51:18 pm
content: Put a 50 Ohm terminator on far end.Sweep Z of S11 using just Ch0. However that won't give the loss, as S21 needs both ends at the cable to be connected.Edit Sorry , RG6 is 75 Ohm.

author: Roger Need
author_rank: Regular Contributor
timestamp: May 10, 2024, 04:53:58 pm
content: Quote from: dobsonr741 on May 10, 2024, 02:04:55 pmIf you leave the far end disconnected you can use the NanoVNA to make the equivalent of a Time Domain Reflectometer (TDR) measurement. This feature is built into the NanoVNA and you will see impedance bumps as blips on the display. If you have a short or an open in the line you will easily see it. Using the cursor you can measure the distance to the blip.You can measure loss vs. frequency by doing a Return Loss (RL) measurement with the NanoVNA. Leave the far end open and divide the RL by two to get an estimate of attenuation loss in the cable. For best results measure with the far end open and then measure with the far end shorted. Then Atten. = (RLo +RLs)/4. Attenuation estimate will be betterIf you have a recent version of firmware by DiSlord you can measure several things about your cable by leaving the far end open and using the Cable menu item (under measure).Roger
Open-source Off-Grid Phone Network - Page 1
Forum section: electronics / rf-microwave

author: jonovid
author_rank: Super Contributor
timestamp: April 27, 2024, 01:50:27 am
content: Meshtastic is an open-source mesh network long range off-grid communicatorESP32 is a feature-rich SoC with integrated Wi-Fi and Bluetooth connectivity for a wide-range of IoT applications.
Looking for TX-RX @ 433MHz - Page 1
Forum section: electronics / rf-microwave

author: atomosrl
author_rank: Newbie
timestamp: April 22, 2024, 07:39:07 am
content: Hello everybody,I'm looking for a pair of TX-RX modules @ 433MHz.Something like thisI need 4 channel remote control. I don't need single output (like open collector). I've a microcontroller onboard and I can receive serial signals.I'm looking for European supplier.Any name?ThanksStefano
HTRC110 PSK/FSK tag reading Capabilities - Page 1
Forum section: electronics / rf-microwave

author: alasa995
author_rank: Newbie
timestamp: April 18, 2024, 03:10:58 pm
content: Hello everyone,I need to use HTRC110 to read FSK/PSK modulated tokens (mainly Weigand, HID MicroProx), I found out that the chip is incapable of dealing with such modulation, does anyone have any confirmation and explanation as to why? such modulation should be simple to handle. Any other alternative from NXP? I was using the EM4095 and it used to work just fine.Thanks
Biquad yagi design? - Page 1
Forum section: electronics / rf-microwave

author: cadr
author_rank: Contributor
timestamp: April 28, 2024, 01:45:03 am
content: Does anyone have any references to designing Biquad Yagi antennas?

author: pienari
author_rank: Regular Contributor
timestamp: April 29, 2024, 07:24:16 pm
content: I havent tested yet.https://www.changpuak.ch/electronics/bi_quad_antenna_designer.phpI have made few TwinDeltaLoop antennas to uhf and they were superb.

author: ch_scr
author_rank: Frequent Contributor
timestamp: April 30, 2024, 10:24:01 am
content: This guy gives a few hints in his video(s):

author: cadr
author_rank: Contributor
timestamp: May 01, 2024, 12:03:44 am
content: Thanks.Yeah, his videos are the ones I had seen, but hadn’t found anything written on the subject.

author: miniant
author_rank: Newbie
timestamp: May 01, 2024, 07:00:16 am
content: https://www.qsl.net/yu1aw/ANT_VHF/fid24ghz.pdfMaybe this article can help you. It is well documented and can be a starting point.

author: cadr
author_rank: Contributor
timestamp: May 01, 2024, 09:36:16 pm
content: Quote from: miniant on May 01, 2024, 07:00:16 amThank you! That is a great start.

author: pienari
author_rank: Regular Contributor
timestamp: May 08, 2024, 06:02:41 pm
content: Few links.http://www.ccc-mannheim.de/mediawiki/images/e/ec/Wlan_Anleitung_de.pdfhttp://www.tresselt.de/download/Wlanprojekt.pdf
negative resistance BFU710 SiGe? - Page 1
Forum section: electronics / rf-microwave

author: bnevins
author_rank: Newbie
timestamp: March 30, 2024, 02:21:58 pm
content: The BFU710F data sheet figure 2 shows a negative resistance region.Is this accurate, or is the data an artifact of device heating?(they did not pulse the signals, but applied continuous collector voltage and thetransistor got hot, reducing the current at higher voltages).https:xx //www.rfmw.com/products/detail/ xx bfu710f115-nxp/422514/

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 30, 2024, 03:41:48 pm
content: Not sure why the munged link, you can just direct link the datasheet here...https://www.nxp.com/docs/en/data-sheet/BFU710F.pdfAFAIK, SiGe have extremely high Early voltage, or perhaps even a little bit negative. It probably is a thermal effect as you suppose.It's probably not an oscillation thing, like, parasitic oscillation while the curve tracer is working... it would likely look lumpier than that.Tim

author: MarkT
author_rank: Frequent Contributor
timestamp: April 11, 2024, 08:29:42 pm
content: Maybe its not negative resistance, its gain falling due to temperature rise? Probably clutching at straws though, this is an exotic device compared to a 2N2222 or similar!
Designing of KU Band SSPA use in BUC - Page 1
Forum section: electronics / rf-microwave

author: vino
author_rank: Newbie
timestamp: April 11, 2024, 06:23:38 pm
content: Good Day EEVBlog I would like to seek professional advice in step by step designing of KU band SSPA that will be use in BUC. What are the things that I need to consider? is there any website, articles, books or any other forms of resources that the community can provide to me. Thank you very much any advice and help will be highly appreciated.
FS1000A Transmitter-Receiver ? - Page 1
Forum section: electronics / rf-microwave

author: DELTA67
author_rank: Regular Contributor
timestamp: April 10, 2024, 03:47:27 pm
content: Hi all,I've bouhgt an FS1000A RF transmitter and receiver pair.1- On most photos on the web:- The transmitter has 2 coils, mine has only the big one! Is this normal??- The receiver reference is XY-MK-5V, mine is MX-RM-5V. What's the difference between them?2- I powered the 2 modules with 5V and test the DATA pin of the receiver with a voltmeter, in DC position while the data pin of the trasmitter connected to Vcc (5V) and when it's floating or connected to GND. The result: No difference (about 0V)!!!I suppose that I must add the missing coil on the transmitter, No?3- What are the expected results?- In the case when the data pin of the trasmitter is connected to Vcc (5V).- In the case when it's floating or connected to GND.4- The SAW resonator has R315 as marking, but no thing indicating the working frequency of the receiver.Is there any simple way to know if the modules are paired or not?Thanks

author: DELTA67
author_rank: Regular Contributor
timestamp: April 11, 2024, 05:31:56 pm
content: Well, I'll answer my self!1- Some FS1000A transmitter models have replaced the smaller coil with an smd inductor.but we can add our own coil:https://vk4ghz.com/fs1000a-433-mhz-transmitter-l2-missing2- The transmitter must be powered with 6-12V and must be very close (some cm) to the receiver in order to get some thing.
E4432B example of digital mod to use with Siglent / Rigol Modulation analyzer? - Page 1
Forum section: electronics / rf-microwave

author: EE-digger
author_rank: Frequent Contributor
timestamp: April 10, 2024, 11:47:25 pm
content: I have an E4432b and a recently added modulation analyzer. I can't for the life of me generate a signal that the analyzer can decode.If you can suggest a simple setup that can generate a fixed pattern, that would be great. The analyzer is Siglent SSA3032X+.I've tried Bluetooth (probably classic, original format and speed), various CDMA formats but no luck. I understand the pieces involved but not enough to construct a working signal and a decoding solution.I just want to see a constellation and see recognizable words in the decode box.added - ok, got 16QAM and 32QAM signals working ok, no luck with Bluetooth. The E4432B does not show the symbol rate for Bluetooth so I have to assume original Bluetooth vintage.
Shortening active GPS antenna cable - Page 1
Forum section: electronics / rf-microwave

author: kuzm1nsk1
author_rank: Contributor
timestamp: April 06, 2024, 01:53:44 pm
content: Hi, would it be a good idea to shorten a GPS antenna cable or should I leave it as it is? Cable is 3 meters long but I only need no more than 10 cm. I found online some teardown pictures of an active GPS antenna and spotted probably a matching network right after the cable connection. So that tells me there is impedance matching and the cable can't be random length. Would this make a problem in terms of received power. Could I shorten it in some ratio so it would act like the original?

author: vk4ffab
author_rank: Frequent Contributor
timestamp: April 07, 2024, 01:37:27 am
content: Quote from: kuzm1nsk1 on April 06, 2024, 01:53:44 pmI do not see a problem with cutting it down, but I would ask, is it necessary. As long as the cable loss is not problematic for the application, i would not bother unless you need to reduce it for install neatness and cable management.

author: fourfathom
author_rank: Super Contributor
timestamp: April 07, 2024, 02:06:53 am
content: Quote from: kuzm1nsk1 on April 06, 2024, 01:53:44 pmI'm guessing here, but what looks like a matching network is probably a phantom power splitter. At the receiver end of the cable there is a power injector that uses a capacitor and inductor to feed power down the cable to the preamp at the antenna puck. A similar L/C circuit at the preamp splits off the power and couples in the signal. This is a 50 Ohm system.So, the cable is unlikely to be matched, and could be shortened if you truly need to. I do know that this kind of antenna works well if you add a low-loss extension coax (using proper connectors and adaptors). But your cable would need to be cut and very carefully spliced or (better yet) a new SMA connector attached. This is GHz you are dealing with, so you can't be sloppy. I wouldn't bother, just make a nice coil so the excess stays out of the way.

author: kuzm1nsk1
author_rank: Contributor
timestamp: April 07, 2024, 08:47:04 am
content: I’d like to mount it inside of a box so there isn’t much space for 3 meters of cable. I was planning to dissasemble the antenna case, desolder the cable, shorten it and solder it in the same way it was before. Well, I could buy one more antenna to make an experiment.

author: wasedadoc
author_rank: Super Contributor
timestamp: April 07, 2024, 11:11:19 am
content: As already postulated the coil and capacitor are just the separation of power and signal. Nothing about matching. No problem to shorten the cable as you propose.

author: kuzm1nsk1
author_rank: Contributor
timestamp: April 07, 2024, 12:29:54 pm
content: I'll order a new one just in case and try it out. I should get one of those little VNA-s, they are so useful.
Searching for a program to operate the generator with IC AD9854 (AD9852) - Page 1
Forum section: electronics / rf-microwave

author: max-bit
author_rank: Frequent Contributor
timestamp: March 24, 2024, 07:38:01 pm
content: I am looking for control/control tool softwareAD9854 based generator module (AD9852)Such a generator is still sold today as a ready-made module.While there are modules, the software is a "problem"Found photos of "what it might look like"If anyone has such software, please link it.Thanks.

author: cncjerry
author_rank: Unknown
timestamp: April 06, 2024, 07:04:07 am
content: I have that board. The software was from AD and came with their development board but you were able to download it. Search on "AD9854 development board." I had it running under win7 but it worked best on winXP. I'll look around and see if I still have it. You can also download it frommand some of the ebay sellers. I used the AD software and then I think I wrote my own version. That board really worked well with direct conversion receivers as it has quadrature output.Jerry

author: max-bit
author_rank: Frequent Contributor
timestamp: April 06, 2024, 07:09:34 am
content: I downloaded it AD but it is very old.... probably 2003 and actually somewhere around WinXPthere are applications made by the Chinese (pepole) for currently sold tiles, but it is "hidden"But people don't buy it and the point is that someone who bought and received the program "shares" the software
Repurposing a starlink dish for 3d imaging - Page 1
Forum section: electronics / rf-microwave

author: uganda
author_rank: Newbie
timestamp: April 05, 2024, 06:57:59 am
content: Starlink's dishes nominally would appear promising. Lots of elements, genuinely 3d, high frequency for high resolution. They're also in the $1k range. This is so cheap for a beautiful 3d radar array, thanks among other things to economies of scale.

author: ftg
author_rank: Frequent Contributor
timestamp: April 05, 2024, 03:20:47 pm
content: All the RF beamforming stuff in the Starlinks terminals is currently not documented.It is unlikely that ST or Space X will be releasing the datasheets for them.Another problem is that while the terminal receives on 10.7-12.7GHz, it transmits on 13.85-14.50GHz.The transmit hardware is unlikely to pull down to 10.7-12.7GHz, but many things are possible.

author: uganda
author_rank: Newbie
timestamp: April 05, 2024, 06:31:29 pm
content: Quote from: ftg on April 05, 2024, 03:20:47 pmedit: poor comment below for several reasons, no longer valid, leaving full text for others' entertainment.So most likely this requires a strategic pivot from 3d to 2d, which is still really cool and better than anything anyone is doing with RF phased arrays for imaging in the diy community to my knowledge.This is probably good for other reasons, as it significantly simplifies the control and processing. Now all we need to do is emit unsynchronized pulses, and process when one is received. To keep things simple this will probably require some directionality and shielding to avoid coupling the transmit pulse but we should be able to make a pretty picture (relatively speaking) and it won't have distance info.Is that in the direction of a solid strategy?

author: Marco
author_rank: Super Contributor
timestamp: April 06, 2024, 01:41:33 am
content: Quote from: uganda on April 05, 2024, 06:57:59 amNo, the 4D radar units have 2D emitters. Not very common yet.

author: uganda
author_rank: Newbie
timestamp: April 06, 2024, 06:12:09 am
content: Great news, I was confused thinking FMCW requires sync between rx and tx but obviously it doesn't. So we're back to 3d with a relatively simple unsynchronized separate tx.Quote from: Marco on April 06, 2024, 01:41:33 amYeah they don't look particularly available or easy to find, whereas starlink is readily available and cheap. All the expensive Tesla radars on ebay look really tiny, and they're sealed boxes, not sure if any have 2d arrays.
Disimilar metets in an antenna vertical coil - Page 1
Forum section: electronics / rf-microwave

author: videobruce
author_rank: Frequent Contributor
timestamp: April 05, 2024, 02:32:16 pm
content: I ran into a problem with a dual-band vertical. Long story short, the 'loading coil' was bad, it affected VHF, not UHF. The problem was a poor connection between the 'coil' and the whip 'fittings' inside the assembly (see the attachment), but in this case it wasNOTa 'dissimilar metals issue. The antenna is new, I caught the problem before the antenna was installed (using the separate 'Ground Plane roof mount) on the roof.There was a plastic build-up inside of the plastic 'sleeve' somehow from manufacturing. Here is the antenna;https://baofengtech.com/product/nagoya-nmo-200a/My question is, the metal fittings are chrome coated brass or copper and the coil is either brass or copper from what I can tell. Isn't this a issue with dissimilar metals and the chemical action between them?

author: MarkT
author_rank: Frequent Contributor
timestamp: April 11, 2024, 08:04:40 pm
content: Spring is likely plated steel. The copper spring is a close relative to the chocolate teapot as its such a soft metal, for springs beryllium copper alloy is used. Probably just a poor connection due to oxide film, dirt and or corrosion. Cheapo construction leads to lacklustre performance...

author: videobruce
author_rank: Frequent Contributor
timestamp: April 11, 2024, 08:45:01 pm
content: I did contact them, they sent a replacement and that's fine. I have another one of these, but tuned to the Business Bands that had no problem. Of they I had a spare coil/coupler, that was fine also.Tram has a almost identical setup.Its a "Tram 1180" dual band antenna and a "Tram 1470" ground plane mount, but their mount has a 'N' connector which the Nagoya doesn't have making it a huge plus (in my book). Also the antenna is cheaper since it doesn't have the flexible right angle base and the longer base coil. If i came across that first I would of choose that with the N connector for UHF. I asked Nagoya about the better connector, but all they sell is the old school SO-239.
[solved, amplifier non-linearity issue] SAW filter performance at harmonics? - Page 1
Forum section: electronics / rf-microwave

author: szoftveres
author_rank: Regular Contributor
timestamp: April 05, 2024, 05:26:36 pm
content: I've been experimenting with this filterhttps://www.mouser.com/datasheet/2/3/AFS915_0w03_TS3-2950334.pdfI have a comb generator and able to pick out the ~915MHz content. However I've been observing leak-through (-20dBc rel. to 915MHz) at 1.83GHz. The datasheet doesn't characterize the behavior beyond 1.4GHz hence I'm wondering if this is normal?

author: ch_scr
author_rank: Frequent Contributor
timestamp: April 05, 2024, 06:00:12 pm
content: Just add a single wide LC filter to add the inteded characteristics. Horses for courses.

author: szoftveres
author_rank: Regular Contributor
timestamp: April 06, 2024, 02:36:59 am
content: I have an amplifier right after this filter which I thought was linear at this power level - that's the culprit.
How the iPhone changed the RF-Filters.  SAW to BAW to FBAR to SMR - Page 1
Forum section: electronics / rf-microwave

author: BrianHG
author_rank: Super Contributor
timestamp: March 30, 2024, 12:34:07 am
content: Enjoy:

author: mawyatt
author_rank: Super Contributor
timestamp: April 03, 2024, 02:10:10 am
content: Interesting, thanks for postingWe were fortunate to work directly with Dr. Ken Lakin of TFR Technologies in Bend, Or. with our first silicon fully integrated MW/MMW receivers and later transceivers back in early 90s.Ken was one of the pioneers of early BAW technology, and patented the Back Side Passivated BAW devices which eliminated the need for the chemical etching for standard BAW devices.We wanted to develop a fully integrated silicon receiver with the BAW preselector filter integrated directly onto the active silicon at the wafer level. AlN which was one of the BAW active materials is directly compatible with silicon, so this deemed plausible.For our 1st step Ken developed separate AiN BAW filters which worked quite well, and very successful. However we never got the chance to develop the fully integrated versions as funding became scarce and more effort and $ were put towards the first MW/MMW SoC Transceivers.Later TRF was acquired by Sawtek, which was then acquired by RFMD, then Qorvo I believe.Recall there was also some SAW work done with GaAs back in 80s and 90s with a version which had tunable characteristics.Anyway, very interesting technologies that you don't hear much about today, thanks for postingBest,

author: richnormand
author_rank: Unknown
timestamp: April 03, 2024, 03:15:50 am
content: Thanks for posting. Brings back memories.Did my master on SAW transducers (interdigital) using optical (laser) light diffraction from the surface acoustic waves on lithium niobate to do signal processing faster than conventional electronics at the time....

author: mawyatt
author_rank: Super Contributor
timestamp: April 03, 2024, 02:32:38 pm
content: Quote from: richnormand on April 03, 2024, 03:15:50 amVaguely remember the efforts with LiNbO3 SAWs doing Optical Processing, more details please!!Best,

author: richnormand
author_rank: Unknown
timestamp: April 03, 2024, 06:53:49 pm
content: Would give you a fair period correct intro to the subject:https://opg.optica.org/ao/abstract.cfm?uri=ao-22-18-2810
Sinad Measurement and Modulation Depth / Deviation - Page 1
Forum section: electronics / rf-microwave

author: chick0n
author_rank: Regular Contributor
timestamp: April 04, 2024, 10:18:25 am
content: Hallo,im wondering, what Modulation Depth and Deviation I should set in my Signal Generator, for a Sinad Measurement?What is the Average Modulation Depth / Deviation, of Todays Radio Transmitters and Amateur Radio Transceivers?

author: mag_therm
author_rank: Frequent Contributor
timestamp: April 04, 2024, 01:11:07 pm
content: Ham radio USA FM standards:Below 29.5 MHz, Modulation Index is limited by FCC to 1.0Ref: ARRL Extra Class License Manual 12thEd Page 8-4Above 29.5 MHz, Carson's Rule is used for "good practice", and the total bandwidth is typically approximately 16 kHz (eg for the 2 metre 20 kHz channel spacing.) FCC specifies bandwidth at -26dBRef: ARRL General Class License Manual 9thEd Page 5-10A good reference with spectrum diagram @ Fig 3 is:https://www.arrl.org/files/file/General%20Class%20License%20Manual/About-FM-Silver-QST.pdf

author: RFDx
author_rank: Regular Contributor
timestamp: April 04, 2024, 09:05:02 pm
content: VHF/UHF+/-2.5kHz for NFM (12.5 kHz channels).+/-5kHz for WFM (25 kHz channels).For CB (and 10m ham band) FM deviation is equal or less than +/-2kHz.
LMX2820 PLL board on eBay - Page 1
Forum section: electronics / rf-microwave

author: klondike
author_rank: Newbie
timestamp: March 06, 2024, 07:10:14 am
content: Hi,Has anyone tried the LMX2820 22Ghz PLL board on ebay? How good or bad is the phase noise performance with the stock configuration?I'm planning to feed it with low noise Wenzel ocxo to use as low noise LO for phase noise measurement.https://www.ebay.com/itm/296126831458?_trkparms=amclksrc%3DITM%26aid%3D1110018%26algo%3DHOMESPLICE.COMPLISTINGS%26ao%3D1%26asc%3D261797%2C261915%26meid%3Dfff7824392474bb385f6b72d9f1c8f42%26pid%3D101196%26rk%3D1%26rkt%3D12%26sd%3D355317151095%26itm%3D296126831458%26pmt%3D1%26noa%3D0%26pg%3D4429486%26algv%3DCompVIDesktopATF2V4WithDefaultIMAFeature%26brand%3DUnbranded&_trksid=p4429486.c101196.m2219&itmprp=cksum%3A296126831458fff7824392474bb385f6b72d9f1c8f42%7Cenc%3AAQAIAAABELHyIAEaemKG0mx4REjf%252BHyi2kzcINSWjmv491TDyjbVmYwevKj0ejii%252FeyFe06fKmTkTSCNhTtVKu2TqNYMpWWHBkyu%252B%252FH%252BuDq9PHY4U%252BQf5%252Fq1TiycCEUbygfx1E2hCp%252FRANSFcwChgC2eDyyqSsFtDkXVyEJTLIp0mEKK%252Fh6BYBiSfHN1e2HeKufzXZP1p1En%252F5y%252ByK9%252Bp%252Fxpg%252BttWloDgstzteYa6R%252BMTtCKthQ%252Fh5UzLT8iC7Mi08eTklLqv0CCW%252Feui9Wlq%252BVPNW%252BvkYWqvyMWXGQCcGz8FtWkSOQWRVWZC7GyXbysc8uNiBo17patDIHF4PDM733YBeOPX1eMC%252FokGtu%252BGtya1vp7RkFr%7Campid%3APL_CLK%7Cclp%3A4429486&itmmeta=01HR98HCDKTPFV9NT4QGGXEJB0

author: rfdave#gmail.com
author_rank: Contributor
timestamp: March 07, 2024, 02:30:42 am
content: It's certainly not going to be any better than the datasheet performance, so that would put a floor on the expected performance. The OCXO will only improve performance at BW inside the loop filter BW. The loop filter is external, so you can tweak that somewhat.

author: Aiy
author_rank: Regular Contributor
timestamp: March 09, 2024, 05:14:05 pm
content: It certainly is an interesting board.I didn't know they were this cheap.I'm probably gonna get myself one for experimentationgood find!Best regards

author: jayk
author_rank: Regular Contributor
timestamp: March 27, 2024, 09:27:58 pm
content: Definitely cheap, but that's at most a TCXO (not an OCXO) and it would have been nice if they'd matched the length of both differential outputs.

author: Verticon
author_rank: Contributor
timestamp: April 01, 2024, 11:38:14 am
content: Hi,these boards are damn cheap. The price at Mouser is roughly 115 EUR (quantity 1) for the LMX chip only. Therefore I wonder if they use low quality chips. It also seems that they use simple FR4 material which could explain the level decrease at the high frequency end.Best regards
Great Lakes Agreement (GLA) radios now on 4 year inspection - Page 1
Forum section: electronics / rf-microwave

author: CaptDon
author_rank: Super Contributor
timestamp: March 28, 2024, 01:29:02 pm
content: Greetings marine radio operators!! If you were operating an inspected passenger vessel (NON-SOLAS) on the Great Lakes you were subject to the 13 month inspection cycle. The GLA agreement with Canada has ended and any radio which had a valid inspection in place on 11/2/2022 or since that time is now granted a 48 month (4 year) inspection cycle which begins on the issue date of the current valid inspection. ALL SOLAS vessels will remain in the 13 month inspection cycle. The good news is spending $100.00 to $300.00 every year will now be once every 4 years for many operators!! Cheers mates!!
87104A RF Switch Driver - Page 1
Forum section: electronics / rf-microwave

author: PerArdua
author_rank: Regular Contributor
timestamp: March 21, 2024, 12:10:39 am
content: I have bought a single 87104A RF Switch, and need to build a circuit to drive it.The datasheet for this device (https://www.keysight.com/us/en/assets/7018-06804/technical-overviews/5091-3366.pdf) gives the following steps for operating it (the non-TTL version):• Connect pin 1 to supply (+20 VDC to +32 VDC).• Connect pin 15 to ground.• Select (close) desired RF path by applying ground to the corresponding “drive” pin; for example ground pin 3 to close RF path 1.I do not have any relays to do this, but would prefer a solid state solution. Does anyone know if these pins carry the supply current to GND (200mA per connection)? If so, does this current last for a moment, or continuously whilst the contact is made? I am thinking of using something like the DMN6140L as a low side switch between pins and GND - a low Rdson, 5V compatible, etc.

author: Revky27
author_rank: Contributor
timestamp: March 28, 2024, 07:23:59 am
content: Quote from: PerArdua on March 21, 2024, 12:10:39 amYes I believe the standard drive you need a low side driver for each which directly controls the coil current. You can use a typical low side driver for this: TPL7407LA, however you can find similar which cover the input voltage range up to 32V as this part is only suitable for 24V operation.The datasheet also specifies that it has magnetic latching and together with this information.Supply current, Icc Switching: Pulse width ≥ 15 ms: Vcc = 24 VDC1 Option 024 and T24 200 mA"After the RF path is switched and latched, the drive current is interrupted by the electronic position-sensing circuitry. Pulsed control is not necessary, but if implemented, the pulse width must be 15 ms minimum to ensure that the switch is fully latched. "To summarize: effectively you will need to drive the pin with a low side driver capable of 200mA for more than 15ms. There is some internal circuitry that once the relay is switched and latched the driver current will stop. You also need to ensure break before make: disconnect the current relay drive before you connect another drive pin to GND.
Becoming a ham article in April 2024 Silicon Chip - Page 1
Forum section: electronics / rf-microwave

author: vk3yedotcom
author_rank: Frequent Contributor
timestamp: March 27, 2024, 07:56:38 am
content: If you're in Australia & keen on becoming a ham, go out & buy the April Silicon Chip for an excellent article by David VK3DSM.You can read the first two pages online here:https://www.siliconchip.com.au/Issue/2024/April
Trying to identify RF connector, similar to UHF, but different thread pitch - Page 1
Forum section: electronics / rf-microwave

author: AndrejaKo
author_rank: Frequent Contributor
timestamp: March 23, 2024, 07:54:33 pm
content: So I'm trying to identify some mysterious RF connectors. At first glance, they seem like regular UHF connectors, bun when looked in detail, they aren't.The dimensions are basically the same, but the thread pitch of UHF is different, so a UHF connector can be screwed on only around one turn onto these connectors. It appears that these connectors have a 1.25 mm thread pitch.They have center conductor pin which has two small "wings" which spread out spirally from the pin, and the "wings" seem to act like springs.Center pins are marked with Z which has a circle in its middle, BteSG DGThe little triangular elements are smaller than on regular UHF connectors.The bodies seem to have dark blue/black finish and have shiny metal underneath the finish. There's also a characteristic symbol painted in white paint onto the connector bodies.

author: Andy Watson
author_rank: Super Contributor
timestamp: March 23, 2024, 10:23:25 pm
content: A metric version of the PL259 ?Apparently, PL259/SO239 are available in metric and imperial versions. The imperial has a thread of 24 tpi.

author: A.Z.
author_rank: Super Contributor
timestamp: March 24, 2024, 07:22:32 am
content: see if this can helphttps://messi.it/en/catalogue/rf-coax-connectors.htm
What is the physical meaning of Propagation constant beta in a signal ?  - Page 1
Forum section: electronics / rf-microwave

author: electronic_guy
author_rank: Regular Contributor
timestamp: April 06, 2024, 12:23:12 pm
content: Hi,I’ve seen the propagation constant defined in many RF signals when we use the phasors. Sin(Omega*t - Beta*z) when the wave propagates in z direction, Omega being the angular frequency. Beta is defined as 2*Pi / Wavelength. What is the physical meaning of this constant ? How does it relates to the phase of the signal and propagation of the wave through the transmission line? Please explain in a basic sense of it.Thank you.

author: mag_therm
author_rank: Frequent Contributor
timestamp: April 06, 2024, 01:37:09 pm
content: I think you refer to the imaginary part of PP is one of the 3 secondary line coefficientsP = sqrt( (R+jwL)*(G+jwC) )where R,L,G,C are the primary line characteristics measurable/lengthRe(P) is the attenuation CoefficientIm(P) is the wavelength Coefficient (2*pi/Lamdba) *****op's query***Im(P) gives the distance along the line where the phase has changed by 2*pi)and practically related to calculating line (eg coax) velocity factor.Someone may be able to give current reference to the secondary coeficients. My book is too old.

author: radiogeek381
author_rank: Regular Contributor
timestamp: April 07, 2024, 04:15:58 pm
content: The equation you’ve posted describes the propagation of a real wave in space. (No imaginary parts needed.)As you know, the omega t part is the time varying aspect of the wave. If you were standing in one place, the amplitude of the wave would vary as sin omega t.But the wave is propagating through space — in the z direction in this case. So it will vary there too, since the instantaneous change in amplitude at the source can’t appear everywhere at the same time — the speed of light says the oscillation must take time to propagate from z0 = 0 to some other z. That’s where the beta z comes in. Notice that the units of beta are in radians per meter. (omega = radians / second c = meters / second) so radians per meter. That makes sense because radians per meter times meters gets us radians. Just like 2 pi f t gets us radians.So the beta term accounts for the propagation of the wave through a distance.
odd mode oscillations modeling question - Page 1
Forum section: electronics / rf-microwave

author: john23
author_rank: Frequent Contributor
timestamp: March 21, 2024, 01:36:59 pm
content: Hello , the is this good article which shows a phenomena called odd mode oscillations.When we connect amplifiers in parallels we can have odd mode oscilations.the article says that there are conditions for odd mode oscillations.however i cant see the schematics in the article.I have a non linear model a power dividing network S-params and ADS ,could you please give me an example on how i can see these odd mode oscilations?https://www.qorvo.com/products/d/da004854Thanks.
Testing modulation analyzer, what type modulation for digital FM sidebands,  TV? - Page 1
Forum section: electronics / rf-microwave

author: EE-digger
author_rank: Frequent Contributor
timestamp: April 02, 2024, 10:55:59 pm
content: Just running some quick tests on a modulation analyzer and find myself short of food for it. What type of modulation is used for digital FM sidebands?What are the offsets from the carrier?How about cable TV channels? What can I find on a Comcast / Xfinity cable?

author: radiolistener
author_rank: Super Contributor
timestamp: April 02, 2024, 11:25:52 pm
content: This is NRSC-5, seehttps://en.wikipedia.org/wiki/HD_Radioandhttps://github.com/theori-io/nrsc5

author: EE-digger
author_rank: Frequent Contributor
timestamp: April 03, 2024, 01:54:22 am
content: Thanks for pointing in the right direction. I looked up the standard for NRSC-5-D and it will give me enough to read for a while.
NRVD does not recognize URV5-Z4 sensor  - Page 1
Forum section: electronics / rf-microwave

author: cmu2017
author_rank: Contributor
timestamp: March 02, 2024, 04:41:01 pm
content: I bought a URV5-Z4 sensor as shown in the image below. Only my NRVD doesn't recognize it. Is this sensor only suitable for the older URV5 millivoltmeter type, or is the sensor simply damaged?

author: KeBeNe
author_rank: Regular Contributor
timestamp: March 14, 2024, 04:05:23 am
content: Hi,the sensor works with the NRVD, I also have it in use

author: veedub565
author_rank: Frequent Contributor
timestamp: March 15, 2024, 02:04:50 pm
content: I also have an NRVD with URV5-Z4 and I can confirm it works.

author: cmu2017
author_rank: Contributor
timestamp: March 16, 2024, 10:54:10 am
content: Thank you for your response. Because it didn't work, I started to have doubts. So this one is broken and is being returned to the seller
building united DC biasing network for MACOM amplifier - Page 1
Forum section: electronics / rf-microwave

author: john23
author_rank: Frequent Contributor
timestamp: March 09, 2024, 03:39:13 pm
content: Hello, there is an amplifyer which has a very uniques biasing network describes below in the datasheet and gerber file attached.https://cdn.macom.com/datasheets/CGHV1A250F.pdfI want to power 4 such amplifyer in parralel.I have an RF dividing network which is two layers PCB.I dont have a realistic model of the amplifier. I only have gerbers , the BOM the datasheet and i need to design network which would bias 4 such amplifies is parraelel.also this amplifier sits on 10mm copper heat sink as shown in the attached photo.Is it possible?If yes i would like to know how practically to do i make this big network which whould feed all four amplifiers simultniosly.Thanks.

author: Uunoctium
author_rank: Frequent Contributor
timestamp: March 11, 2024, 01:45:28 pm
content: I. You may solve that problem with Wilkinson divider/combiners. (but i have not any clue on this)example // totally different Freq. range!https://www.microwavejournal.com/articles/print/5719-plug-and-play-power-solution-modules-for-l-and-s-band-pulsed-radar-applicationsII. In my humble opinion mostly preferred solution in eg cellcom PA output amplifiers is to combine the single transitor stages with 90° hybrides, but this solution needs at least 6 pcs. And three of them must be capable of handling the high output power! To avoid any phase shift between, each stage is powered with near complete symmetrical constructed power feed.Bias stages to transistors are also separated and individually adjusted.example // tiny 2140MHz PA ~ 150W