hybridfree/eevblog-posts huggingface dataset:
Identify coaxial relay parameters (KSM KLS21032P) - Page 1
Forum section: electronics / rf-microwave

author: Yansi
author_rank: Super Contributor
timestamp: October 09, 2020, 06:28:02 pm
content: Hello,bought a bunch of used SPDT coaxial relays from Ebay quite cheap - with one unpleasant issue: There is no datasheet for them (at least my google-fu is too weak to find it).It seems there are lots and lots of these exact coaxial relays through the whole Ebay. They are "KSM" brand, type KLS21032P.Anyone happens to know anything about them? Have a datasheet or luck finding one?The only thing I know for sure they are latching 2-coil type, 12V coils. Not even a clue about any other parameters. I am quite interested as to what is likely the maximum usable frequency?Of course one could measure it. But my home lab can't go above 3GHz scalar measurement. Likely I couldn't even measure the insertion loss very precisely, only guesstimate the port isolation. (My SA is old tech, can't do very precise level measurements).3GHz VNA instrument is the top I could access if ever. (But guessing usable frequency range of these may extend well above 3GHz).Thank you for any clues to identify these. Photo below, the color cable is not original, I have added that one, due to original terminals being broken off.
Are the MSK & FFSK modulation techniques same? - Page 1
Forum section: electronics / rf-microwave

author: madhu.wesly01
author_rank: Regular Contributor
timestamp: October 09, 2020, 08:32:59 am
content: Hello,I would like to know if the modulation techniques MSK and FFSK[Fast FSK] both are same?In the below ref: I read this - "MSK is sometimes referred to as ‘fast FSK’, as the frequency spacing used is only half as much as that used in conventional non-coherent FSK". Kindly let me get clarification.Ref:https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwiB0Nal16bsAhUzguYKHTuoBRoQFjAIegQIChAC&url=http%3A%2F%2Fwww.atlantarf.com%2FFSK_Modulation.php&usg=AOvVaw3elQLoHwvn3kPZfFCpfcuZIf they are different - please confirm this a RF transceiver which supports MSK, does it also support FFSK?TIA.

author: madhu.wesly01
author_rank: Regular Contributor
timestamp: October 09, 2020, 04:38:50 pm
content: Resurfacing..Thank you very much for any help.
In the case someone is intererrested into the Austrian Frequencys - Page 1
Forum section: electronics / rf-microwave

author: Lord of nothing
author_rank: Super Contributor
timestamp: October 07, 2020, 07:34:07 pm
content: I found a list of the TV, Radio, DAB+ Channel.Its possible to switch to English Language to:https://www.rtr.at/de/m/MUX
High frequency transformer - Page 1
Forum section: electronics / rf-microwave

author: yalect
author_rank: Regular Contributor
timestamp: October 01, 2020, 05:17:22 pm
content: Hello,I would like to ask you aboutYH12Vhorizontal transformer discription of its properties or Datasheet and usage examples, I read that it works with high frequency.thanks

author: bob91343
author_rank: Super Contributor
timestamp: October 01, 2020, 07:14:52 pm
content: You will need to give a more complete description of what you have and what you want.

author: geggi1
author_rank: Frequent Contributor
timestamp: October 01, 2020, 09:12:28 pm
content: I did google it and found it on Aliexpress.It looks like a regular telecom transformer.Comparing to a regular transformer (50/60 Hz) it can be considered as a high frequency transformer at 2khz to 4 khz depending the maximum frequency and internal reactance i the windings.

author: yalect
author_rank: Regular Contributor
timestamp: October 02, 2020, 09:13:02 am
content: what about the volte and Conversion ratio?thank you

author: geggi1
author_rank: Frequent Contributor
timestamp: October 02, 2020, 09:02:46 pm
content: There is no information on the vendors page.You must contact your supplier for a datasheet for the transformer.But normally a telecom transformer is 600/600 ohm.

author: yalect
author_rank: Regular Contributor
timestamp: October 03, 2020, 05:17:57 pm
content: thank youyou mean its ratio is 1?

author: geggi1
author_rank: Frequent Contributor
timestamp: October 03, 2020, 07:21:20 pm
content: yes 1:1 ratio.

author: TheMG
author_rank: Frequent Contributor
timestamp: October 06, 2020, 12:05:55 am
content: If no datasheet can be found online, contact the seller. If the seller can't provide the specs, then you're out of luck.Looks for all the world like a SMPS transformer. The specs could be absolutely anything, there's no way to know, it's probably not a standard part, most likely surplus from a production run of a custom transformer for a specific power supply design.
Need help / pointers in hunting down source of RFI? - Page 1
Forum section: electronics / rf-microwave

author: eenewb
author_rank: Newbie
timestamp: October 05, 2020, 05:44:36 pm
content: Hi everyone! I am a software engineer who has some basic experience with electronics and have been noticing that electronics around me emit high pitch noises to the point where I'm able to measure (and hear) them. I understand that some noise is normal, but at the levels that I'm seeing, I'm wondering if this is within normal parameters.Here are some screenshots of some of the measurements I've taken (audio spectrum plot): Please keep in mind that these spikes are above the noise floor, making them distinct and audible (to those who can hear these ranges).Any thoughts on this would be greatly appreciated!!(Below: My washing machine)(Below: A Black Diamond headlamp)(Below: My car's environmental control cluster)(Below: A DJ Media player (Denon SC5000))

author: cdev
author_rank: Super Contributor
timestamp: October 10, 2020, 10:19:54 pm
content: you could make a probe, perhaps with an attenuator built in, so you could hunt the source down.If its a coil, a dab of hard glossy fingernail polish might quiet the whine. Thats worked in the past for me.

author: David Hess
author_rank: Super Contributor
timestamp: October 13, 2020, 02:32:05 am
content: A microphone attached to a straw makes a good probe for searching a single circuit board or enclosure.

author: cdev
author_rank: Super Contributor
timestamp: October 14, 2020, 03:02:49 am
content: Thats what I use too. Its amazing how much you can hear on electronics PCBs doing that. Most inductors and some capacitors also emit sounds.I also recently ordered some real EMC probes, they appear to have been a really good deal, we'll see when they get here.I also recently swapped out my old keyboard for a newer one and it appears that some of the noise was likely coming from it.Quote from: David Hess on October 13, 2020, 02:32:05 am
RF Explorer networked - Page 1
Forum section: electronics / rf-microwave

author: JohnWW
author_rank: Contributor
timestamp: October 05, 2020, 07:03:34 am
content: Hi FolksLooking for any details for networking RF Expolorer Iot on top of a rasberry pihttp://j3.rf-explorer.com/182.I am thinking being able to run multiple RF explorer on a network and for people to veiw scans.ThanksJW
Phase detector sub - Page 1
Forum section: electronics / rf-microwave

author: cncjerry
author_rank: Unknown
timestamp: October 01, 2020, 07:27:54 am
content: I normally would use a minicircuits sypd-1 for a project but ran out of them and with a MOQ of 10, the next batch would be $140 + shipping and I need one. I checked the usual places without kuck. This application is from DC to 1Mhz on the IF port and up to 10Mhz on the RF and LO ports. I am hoping to hear from a friend who had a few but in the meantime I wondering if there are other more available subs?z. Balanced mixers work as PDs and also remember a NASA paper on using descrete transistor junctions as diodes to make a balanced mixer that had really good performance but can't find it. Any ideas?ThanksJerry
Tektronix RSA-DKIT - Page 1
Forum section: electronics / rf-microwave

author: electrolust
author_rank: Unknown
timestamp: September 04, 2020, 09:36:24 pm
content: RSA-DKIT is the Tek "RTSA V3 Demo Board". AFAICT produced with the launch of USB SAs (eg RSA306A). V3 was apparently produced 2014-2016. It's been discontinued and I can't find hide nor hair of it. Anyone familiar with this, or maybe have one they can part with? Or know of a similar demo/training board? Not the NanoVNA board that is everywhere.

author: electrolust
author_rank: Unknown
timestamp: September 30, 2020, 07:08:52 pm
content: Done some research on this. $1200 new. $300 on ebay currently.https://www.ebay.com/itm/Tektronix-Cage-80009-Board-Assembly-863-0850-0/283919090662These pretty much don't exist used and without a proper PN (eg the above one is listed incorrectly) good luck. I bet the seller will take $200.
85053B Data File - Page 1
Forum section: electronics / rf-microwave

author: clockspectrum
author_rank: Contributor
timestamp: September 25, 2020, 03:27:08 pm
content: I have a 85053B verification set that I need to get the data off of the original HP backup tape. I believe the tape was originally used with the 8510 VNA. I really don't want to send the set in for calibration because this is more exploratory in nature. I was wondering if anyone out there had the ability to pull the data off this tape for me. Also, any cal data that you may have would be better than anything. Any help would be much appreciated.MattRaleigh, NC

author: TheSteve
author_rank: Unknown
timestamp: September 26, 2020, 03:02:56 am
content: My 85053B included the tape and floppy disks. It took some effort but I was able to get all of the data from the floppy disks(in LIF format). Not only do you need someone with a matching tape drive but they will also need a way to store the files in another format once they can read them. Or buy yourself a HP tape drive from ebay and try to read the tapes via GPIB manually.

author: clockspectrum
author_rank: Contributor
timestamp: September 27, 2020, 05:37:56 pm
content: Ive considered buying the display processor (85101) for the 8510 for a couple hundred dollars and try to pull the data. What external HP tape drives were produced that could read these tapes?

author: rf-messkopf
author_rank: Regular Contributor
timestamp: September 29, 2020, 12:05:22 pm
content: Quote from: clockspectrum on September 27, 2020, 05:37:56 pmThe tape cartridges are these:http://www.hpmuseum.net/display_item.php?hw=265.Quote from that website: "For years now, reading data from these old tapes has been almost a lost cause. The last mainstream computer that HP made which used these tapes was obsoleted in 1987 (the 85B). It is extremely rare to find a drive that will read one of these tapes unless that drive has been refurbished. [...] In our experience, fewer than 15 percent of these old tapes are readable."Probably it is not worth investing in trying to read them.I have a HP 85053A verification kit that came with a tape and three disks in LIF format. I had them read by a helpful user in the German mikrocontroller.net forum, see this thread here:https://www.mikrocontroller.net/topic/470073(in German).
TCVCXO Oscillator Tolerance Calculation Question - Page 1
Forum section: electronics / rf-microwave

author: rcbuck
author_rank: Frequent Contributor
timestamp: September 28, 2020, 01:13:27 am
content: If I have a 20.000 MHz TCVCXO Oscillator that the data sheet says tolerance is 2.5 ppm, what is the tolerance at 200 kHz?Performing this calculation: 20000000/200000 = 100 therefore 2.5/100 = .025 per 1000. Is this correct?So if the 20 MHz signal is divided down to 200 kHz it could be off by +/- 5 Hz. Is this correct?If I use the same 20 MHz oscillator to lock a PLL to 100 kHz, what would the tolerance be in that case?

author: MasterT
author_rank: Frequent Contributor
timestamp: September 28, 2020, 03:51:01 am
content: Quote from: rcbuck on September 28, 2020, 01:13:27 am1. Not correct.2. 200 000 * 2.5 *10^-6 = 0.5 Hz3. 100 000 * 2.5 *10^-6 = 0.25 Hz

author: rcbuck
author_rank: Frequent Contributor
timestamp: September 28, 2020, 05:55:51 am
content: MasterT,Thank you for the answer. My calculations looked correct to me. But looking at you calculations I see how mine were wrong. I will put this reference in my notebook for future use.

author: radiolistener
author_rank: Super Contributor
timestamp: September 28, 2020, 09:41:37 am
content: Quote from: rcbuck on September 28, 2020, 01:13:27 amwhen you divide/multiply frequency, it's error is also divided/multiplied. So, it will be the same 2.5 ppm at any frequency.200000 * 2.5/1000000 = 0.5 HzQuote from: rcbuck on September 28, 2020, 01:13:27 amthe same 2.5 ppm100000 * 2.5/1000000 = 0.25 Hz

author: rcbuck
author_rank: Frequent Contributor
timestamp: September 28, 2020, 09:30:17 pm
content: Thanks radiolistener. I actually wanted to know the Hz tolerance number and both your method and MasterT's method give me that number.
HMC307 GaAs IC digital attenuator - Failure Modes? - Page 1
Forum section: electronics / rf-microwave

author: NY2KW
author_rank: Regular Contributor
timestamp: February 25, 2020, 02:35:26 am
content: I am repairing a R&S SM300 signal generator. Originally it couldn't output more than -26dBm but I got it fixed replacing a an RF amp (AGB3303) at the end of the attenuator chain. Now it all works linearly from -120 to +13dbM and flat across 0.5MHz - 3 GHz BUT at any power level, it 12 dB low, e.g at maximum 13 dBm it is outputs 1 dBm. R&S won't share a schematic but the block diagram gives a lot of information (see below). In the final RF chain, there here are 4 HMC307's digitally controlled (see attached datasheet), the last 3 are shown in the Block diagram as 0/30dB all or none, while the first HMC307 is 0-30 dB in 2 dB steps. Could a HMC307 fail so that 2 of the GaAs transistors are not switching out both the 4db and 8db paths? I guess it could also be a problem with the ATT control chip but I cannot see it as there is a lot of soldered down shielding and removing them is above my skill grade. Any advice appreciated.

author: NY2KW
author_rank: Regular Contributor
timestamp: February 25, 2020, 02:36:54 am
content: Here is a picture of the RF PCB:

author: chick0n
author_rank: Regular Contributor
timestamp: September 22, 2020, 05:48:44 pm
content: Hidid you ever find a solution.I had same problem with my sm300. I replaced blown AGB3303, but output is still about 4dB down.
Birdies on a kenwood ts-850s - Page 1
Forum section: electronics / rf-microwave

author: m3vuv
author_rank: Super Contributor
timestamp: September 07, 2020, 01:26:47 pm
content: Hi all,im not sure if this should be here or in the repair section,here goes anyway,the tx/rx relay went intermitent on rx,i found one in an old cb amp i had so wired that up using short bits of coax,see pic,ever since ive noticed the radio seems to have birdies on most bands that read about s3,thats without my antenna connected,on the bits of coax i used i only grounded the relay end of the cable shield,not both ends,could this be causing this issue?,cheers m3vuv

author: m3vuv
author_rank: Super Contributor
timestamp: September 07, 2020, 04:04:02 pm
content: maybe i should ask the question does coax meed to be grounded at each end of the run to act as a shield against rf?

author: bob91343
author_rank: Super Contributor
timestamp: September 07, 2020, 09:04:00 pm
content: Coaxial cable is not intended to serve as shielded wire. It's intended to be a transmission line. When you decide which purpose you want it to serve, the answer to your question will be obvious.

author: m3vuv
author_rank: Super Contributor
timestamp: September 07, 2020, 09:08:27 pm
content: so does that answer what i asked?,looks like a question answered with another question to me.

author: emece67
author_rank: Frequent Contributor
timestamp: September 08, 2020, 07:37:50 am
content: .

author: m3vuv
author_rank: Super Contributor
timestamp: September 08, 2020, 09:40:18 am
content: thanks,ive now done that,seems to have helped things a lot.73

author: Raindog
author_rank: Contributor
timestamp: September 15, 2020, 03:26:47 am
content: Greetings, it appears that most of your questions have been answered but I am guessing if you are still receiving birdies is because of your relay placement. It's an non-shielded relay and more than likely receiving birdies from the DDS board. You may want to consider placing it away from the DDS module or if possible or use a shielded coax relay with SMA fittings. 73. I have this very same transceiver, it's been a real work horse and is still my primary HF rig.
Connector question - Page 1
Forum section: electronics / rf-microwave

author: cncjerry
author_rank: Unknown
timestamp: September 28, 2020, 05:06:41 am
content: I have a couple Motorola daughter cards that would normally sit inside a GPS unit and plug onto the comm and power board. They are M12s, I believe. I had used one in my Lucent/Symmetricom REF0 or REF1, whichever didn't have the GPS to make it standalone. The card plugged right in, by the way. I bought two, one to upgrade the other REFx unit and one to replace in the GPS I took it out of. I used the pigtail that I need now.On the pigtail is a connector that plugs into this card that's about 1.5"x 3'? It is a very small RF connector for the GPS antenna. It is much smaller than an SMA/SMB and is a push-on. It has a pin inside of it. It might be a U.FL but I've only ever seen those on PCBs. This is an edge connector more or less.I'll post a picture if I don't get any hits here, just that it is packed away but I'm going to be bringing it alive shortly and wanted to get the cable order.ThanksJerry
Hacking with self resonance in a Pi-matching network to pass EMI compliance - Page 1
Forum section: electronics / rf-microwave

author: MicroBiggerThanMM
author_rank: Contributor
timestamp: September 12, 2020, 02:03:48 am
content: Hello, as many of you know, and are possibly loathsome of, the FCC cares about your device's emissions up to the 10th harmonic of its highest clock. That makes compliance testing with a 2.5GHz transceiver expensive when the HackRF no longer suffices.In a RF antenna-focused design which has a 2.5GHz antenna the pi-type matching network can help shape your bandwidth to where you want it to operate, but you might still get harmonics from the general frequency you're operating at.I've seen a lot of components listed for self resonance at around the harmonics of 2.4 GHz and am thinking I can use a prime number based method to kill harmonics.In crypto, you can generate good pseudorandom number generators given matched seeds of primes which have a repeating period of the product of the two primes (or their GCD or something, I forgot).So, if you use parasitic component resonant frequencies, you might be able to kill off harmonics!I hope somebody's seen this before so I know this is safe and not silly!Here's how it works,If you replace the single inductor in the pi network for two inductors of lower inductance but self-inductive frequencies of 4.8 and 7.2 GHz, you will essentially knock out the 4.8GHz, 7.2GHz, 9.6GHz, not the 12 GHz, the 14.4GHz, not the 16.8 GHz, the bee's dick 19.2 GHz, the ant's dick 21.6GHz, and finally, my dick, 24GHz emissions.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 12, 2020, 08:02:04 am
content: Heh, filter stopbands don't go geometrically with the number of component resonances, it's one for one.You can indeed tune a filter, parasitically or otherwise, to provide nulls at desired frequencies. It's just as tricky as any other filter tuning exercise, subject to the same tolerances.An easy way to avoid this is to use a certified module, with recommended antenna if it's not onboard already. As modules are abundant, it's unusual to need certification for that particular aspect. The rest of your product need only be tested for its clock frequencies and harmonics.Tim
Antenna Compatibility - Page 1
Forum section: electronics / rf-microwave

author: girishv
author_rank: Regular Contributor
timestamp: September 10, 2020, 05:30:22 am
content: Recently I bought passive components kits put together by AVX. The kit had antennas manufactured by Ethertronics, an AVX group company.Part No. P822601 / P822602Universal Broadband FR4 Embedded LTE / LPWA Antenna698 – 960 MHz / 1710 - 2690 MHzSupports: Broadband LTE (OCTA-BAND), LTE CAT-M, NB-IoT, SigFox, LoRa, Cellular LPWA, RPMAPart No.1002289LTE / Cellular Wide Band FPC Embedded Antenna700 / 750 / 850 / 900 / 1800 / 1900 / 2100 / 2700 MHzSupports: Broadband LTE (OCTA-BAND), LTE CAT-M, NB-IoT, SigFox, LoRa, Cellular LPWA, RPMA, FirstnetI am wondering if I can use these antennas for 2.4GHz WiFi bands?

author: hagster
author_rank: Frequent Contributor
timestamp: September 10, 2020, 05:58:42 am
content: It dependsThe second one specifies performance over the WiFi band so might be ok. The first has a gap from 2.4 to 2.5GHz, so it's a gamble. Neither seem to mention the 5GHz band.My hesitation in giving a more definitive answer is because these antennas rely heavily on the ground plane of the rest of your board. Any changes at all from the specified test setup will alter the performance. Potentially significantly.The gain figures presented are probably directionality and don't include losses(or VSWR mismatches). So that 58%efficiency is close to 3db of loss you can remove from the gain plots to get the a real world metric(realized gain).The only real way to tell how well they work on your specific device is to test and measure it. The effort you put in will obviously depend upon the performance you need.

author: girishv
author_rank: Regular Contributor
timestamp: September 10, 2020, 06:11:10 am
content: Quote from: hagster on September 10, 2020, 05:58:42 amI got them as part of passive components kit. It was a quite surprise to see antennas as I did not know they were part of the kit. The datasheet never talked about the antennas being part of the kit.I would not put too much effort to used them for WiFi bands. I will save them for future use.
Servicing a 750'/220m broadcast tower - Page 1
Forum section: electronics / rf-microwave

author: GeoffreyF
author_rank: Regular Contributor
timestamp: February 05, 2019, 09:08:33 pm
content: This is really pretty remarkable. Some body has to do it. This particular youtube channel is fun. It's filled with videos like this.GeoffKC1KNS

author: 0culus
author_rank: Super Contributor
timestamp: February 06, 2019, 06:31:19 pm
content: ...and definitely not me...I can't even stand a normal residential roof.

author: m3vuv
author_rank: Super Contributor
timestamp: September 07, 2020, 02:15:55 pm
content: i would need a few spare pairs of brown trousers for that job ,too say the least!

author: HB9EVI
author_rank: Frequent Contributor
timestamp: September 07, 2020, 06:09:17 pm
content: I'd try to imagine it was a Via Ferrata somewhere in the Alps, then it might work for me, though 225m free air under the feet likely feel different when being in touch with solid rock; a tower might be another kind of experience after all

author: bill_c
author_rank: Regular Contributor
timestamp: September 07, 2020, 09:04:56 pm
content: How about 1768'

author: m3vuv
author_rank: Super Contributor
timestamp: September 07, 2020, 09:17:31 pm
content: they both need a checkup from the neck up!!!

author: mansaxel
author_rank: Super Contributor
timestamp: September 07, 2020, 10:10:30 pm
content: Quote from: HB9EVI on September 07, 2020, 06:09:17 pmTowers and masts (The definition in Sweden is that a mast is guyed, a tower is self-supporting) sway. Alps don't.I've only done some 10 meters via ferrata en route to Pigne d'Arolla, and only some smaller towers and masts. IIRC my record is 27 meters, and that was indoors, a lighting grid in a hotel foyer. My experience is you get used to it. You simply have to practice being enough used to it to be able to work, but not so used to it that you get careless. There is a lot of procedure you simply have to follow or you'll end up a wet spot on the ground.

author: babysitter
author_rank: Frequent Contributor
timestamp: September 08, 2020, 09:42:14 am
content: You lucky guys, either fear of height or no fear is easy. My brain decides based on moon phase and ambient pressure it seems.In the early 00 years I was Co-Sysop of a amateur television repeater at the 254m and 264m Platform of a steel lattice broadcast tower of Deutsche Telekom. No problems there, immediate adaption to moving there and using the safety stuff. Enjoyed the great view too, never dropped a tool, wohoo!But first I had to go to safety training on a lower ~100m tower (german Bundespost FMT style concrete beauty), not feeling very well up there, but passing the safety training and examination.Sometimes being at, say a balcony at the 3rd floor triggers me and makes me willing to leave, sometimes being on lookout towers is great, sometimes i feel not well. Some rooftops OK, some not. At the scenic "Diana" lookout in Karlovy vary it was strange: great first but then it turned to "Take the elevator down when available." (Which in turn caused the greatest accidental encounter there.)Is there a "selective" fear of height in DSM-IV already?
basic information CMU200 - Page 1
Forum section: electronics / rf-microwave

author: jean françois
author_rank: Contributor
timestamp: September 05, 2020, 01:30:51 pm
content: Good morning all,delighted to come to this great blogg, I read everything about the CMU200. I am in the process of purchasing a CMU200, the goal being analog maintenance. given the complexity of this device, I would have need to clarify some points for the moment not knowing this device.The sale comes from the death of a friend, for me it is very important.But there is no one to inform me.there is no audio option B41, but does that mean that there is no audio signal available (two tone measurements) on the front panel and no audio measurements possible?is this option easily found? at an affordable price? is it easy to install?in basic version: is the RF4 50w input an option? or only 2w original?in the basic version there is only one HF generator?is the TG easy to install?I can indicate the references of the device:CMU-K45 version 5.21 (1100.0008.02) intel celeron 256mb version V850020506.The options: B21V4, B52V14, B56V14, B, B68, B95.in advance thank you if someone can think of my request this device is fabulous and the 3ghz spectrum is for me more certain.thank youAJF

author: switchabl
author_rank: Frequent Contributor
timestamp: September 05, 2020, 01:52:17 pm
content: Quote from: jean françois on September 05, 2020, 01:30:51 pmYes, B41 is required for the audio generator and audio measurements. You can sometimes find them on eBay, but I wouldn't necessarily count on affordable. If you can get the module, it should not be hard to install.Quote from: jean françois on September 05, 2020, 01:30:51 pm50W on RF1 is default, unless option B96/B99 (second TX channel) is present.Quote from: jean françois on September 05, 2020, 01:30:51 pmYes. Option B95 adds a second "AUX" generator, I am not sure what the specs for it are though.Quote from: jean françois on September 05, 2020, 01:30:51 pmThis should have the AUX generator, 50W input (and GSM/CDMA signalling if you care for it). But, no audio generator/analysis.
Transport of an old GTEM cell - Page 1
Forum section: electronics / rf-microwave

author: wilhe_jo
author_rank: Regular Contributor
timestamp: September 14, 2020, 06:41:03 am
content: Hi there!I aquired an old GTEM cell for a very, very good price. The only problem is, I live in Austria where the cell is in the UK.So in the current situation (several restrictions in the UK, France and Austria), I'll need to hire someone to bring it over.Anyone gone through that endeavor in the past?I'd be interested to hear what measures you installed to keep everything intact...RegardsJohann
Invitation to write for RSGB - Page 1
Forum section: electronics / rf-microwave

author: Ultrapurple
author_rank: Super Contributor
timestamp: September 02, 2020, 11:06:37 am
content: Would you like to see your work in print?The Radio Society of Great Britain publishes a monthly magazine,RadCom, and we are looking for possible new authors for technical articles.More specifically, if you have a previously unpublished project related to amateur radio – or just an idea for one in the future – we would like to hear from you, with a view to it becoming an article inRadCom.This invitation is open to all, whether licensed amateurs or not, from any country. We just ask that you use English, because that’s the only language we’re any good at.We can give you as much or as little editorial support as needed. And we pay for the material we publish, though it won’t make you rich.We havea really clunky web page with more information and direct contact details; please look there for a more detailed description of what we're looking for and how to proceed.Even if you've never written anything before, let alone had it published, your idea may be well worth sharing with readers around the world viaRadCom. And it'sniceto see your own work – and name – in print!Giles, G1MFGRadComTechnical Editor

author: cdev
author_rank: Super Contributor
timestamp: September 02, 2020, 10:18:14 pm
content: There has got to be an interesting story involving Jimi Hendrix and circular polarization of antennas out there. I came to the conclusion that at some point during his military service, he must have encountered satellite communications equipment, specifically antennas...... Look at the following with the eyes of an RF engineer..https://www.bibliotecapleyades.net/bb/hendrixj.htmThis idea was incorporated into a park in Seattle, where he grew up..https://www.seattle.gov/Documents/Departments/ParksAndRecreation/Projects/JimiHendrix/JimiHendrixSchematic.pdf
BNC plug cable compatibility - Page 1
Forum section: electronics / rf-microwave

author: kaevee
author_rank: Regular Contributor
timestamp: September 01, 2020, 02:52:39 am
content: I am new to RF. Recently, I bought 75Ω BNC Plugs 5413589-3.https://www.te.com/global-en/product-5413589-3.htmlAfter the purchase order went through, I noticed the cable compatibility is limited Belden 8218, JIS 2.5C-2V. What are the implications if I use with RG59/U coaxial cable?

author: Monkeh
author_rank: Super Contributor
timestamp: September 01, 2020, 03:26:07 am
content: The implication is there's no physical way an 'RG59/U' style cable will fit in a connector intended for a significantly smaller cable.

author: kaevee
author_rank: Regular Contributor
timestamp: September 01, 2020, 03:39:14 am
content: Quote from: Monkeh on September 01, 2020, 03:26:07 amMy bad. I could have checked the cable size before posting. Thanks you very much.

author: TimFox
author_rank: Super Contributor
timestamp: September 01, 2020, 04:43:56 pm
content: At the connection end, 75 and 50 ohm BNCs are compatible (i.e., will mate non-destructively), but 75 and 50 ohm N connectors will not mate.
miniVNA Tiny + or Reflection Bridge for SSA3032X Plus - Page 1
Forum section: electronics / rf-microwave

author: ridgerunnersjw
author_rank: Contributor
timestamp: August 27, 2020, 01:06:24 pm
content: Good morning....I am looking to expand my RF equipment for measuring antennas. Can someone answer a few questions:1. Siglent sells a reflection bridge + software upgrade for the SSA3032X Plus. Does this allow the equipment to become a VNA or just an SNA?2. From the above subject does anyone have any input on which might be the best way to go for a VNA (assuming of course the reflection bridge creates a VNA and not an SNA)? They both are about the same cost ....Thanks

author: DH1AKF_Wolfgang
author_rank: Contributor
timestamp: August 27, 2020, 02:50:29 pm
content: We don't know, what your desired frequecy range is.A really inexpensive VNA are the NanoVNA or NanoVNA-F or NanoVNA V2.I own them all and I'm very happy with each of them.As an example, I could tune my 2.4 GHz Helix antenna for the QO-100 satellite.There is no need for a reflection coupler. All is done with a bridge, inside the VNA.

author: ridgerunnersjw
author_rank: Contributor
timestamp: August 27, 2020, 05:35:58 pm
content: Thanks for response......I'm interested in the 2.4 ISM band....Turns out Siglent is going to take my SSA3032X Plus back, credit my account and ship me the SVA1032X (Spectrum Analyzer and the Vector Network Analyzer all in one) minus the difference that I will pay.After some digging the reflection bridge does not do phase.....

author: DH1AKF_Wolfgang
author_rank: Contributor
timestamp: August 27, 2020, 06:16:21 pm
content: If you can spend some minutes of your time, please have a look at:https://nanorfe.com/nanovna-v2.htmlFor less than 150 $ you could have a really good tool for antenna measurement.Your Siglent is with more than 3400 € outside of my hobby budget.

author: tautech
author_rank: Super Contributor
timestamp: September 01, 2020, 05:39:12 am
content: Quote from: ridgerunnersjw on August 27, 2020, 05:35:58 pmAnd you just won't use it with an SVA as they effectively have the bridge built in on the TG/S11 port.Nice unit and certainly my fav.I've found for sweeping and modifying antennas the SVA is great. Hope you enjoy it.2 threads that might interest you while I was learning about SVA's.https://www.eevblog.com/forum/rf-microwave/antenna-project-log/https://www.eevblog.com/forum/rf-microwave/what-really-is-this-antenna/
Serial Connector for Mini Circuits ZX76-31R5-SP-1+ - Page 1
Forum section: electronics / rf-microwave

author: RobBarter
author_rank: Regular Contributor
timestamp: October 08, 2018, 10:47:56 am
content: Anyone know if the serial connector for the Mini-Circuits ZX76-31R5-SP-1+ digital step attenuator is proprietary or can be bought elsewhere? Have the attenuator but no lead.

author: MatjazB
author_rank: Newbie
timestamp: October 09, 2018, 06:10:02 am
content: Few years ago I was also searching for this connector. Unfortunately I could not find it. I ended buying directly from Mini Circuits.

author: CJay
author_rank: Super Contributor
timestamp: October 09, 2018, 12:49:21 pm
content: The pics aren't great in the datasheet but it looks very similar to an old mobile phone charger/data connector, I'm sure I have some in my office, if I find one I'll dig it out and take pictures.How many contacts does it have?*edit* I've seen some of these on mobile phone charge/data cables:http://www.gsmsolutions.ie/shop/siemens-mains-chargers/289-siemens-mains-charger.htmlI've definitely had them with the retainer clips as well.

author: RobBarter
author_rank: Regular Contributor
timestamp: October 09, 2018, 12:59:21 pm
content: 10 contacts. The socket itself is 10mm across.

author: CJay
author_rank: Super Contributor
timestamp: October 09, 2018, 01:53:52 pm
content: Ahhh, it looks similar to the one used on old PCMCIA cards:http://www.pchub.com/uph/laptop/154-50371-190/3Com-3CCFE574BT-10-100-Z-Dongle-10-100-Lan-.html

author: RobBarter
author_rank: Regular Contributor
timestamp: October 09, 2018, 01:55:46 pm
content: Thanks - I'll have to dig around my many 'rubbish' boxes.

author: switchabl
author_rank: Frequent Contributor
timestamp: August 25, 2020, 10:50:53 am
content: This will probably not help the OP anymore, but maybe someone else finding this topic through Google (like me).The connector is Hirose ST series (https://www.hirose.com/product/series/ST?lang=en), the exact part no. of the plug should be Hirose ST40X-10S-CV(30).

author: RobBarter
author_rank: Regular Contributor
timestamp: August 27, 2020, 07:23:24 am
content: Thanks switchabl. I bought a lead with connector back in 2018 but have held off getting any more ZX76-31R5-SP-1+ due to the lead cost. This may bring me back to using them again. Thanks

author: Lord of nothing
author_rank: Super Contributor
timestamp: August 30, 2020, 05:52:28 pm
content: HiI got a Dell Tablet who have a Mini Serial to. Does anyone know what and how the connector called?https://www.eevblog.com/forum/general-computing/adatper-for-a-mini-serial-port/msg3197788/#msg3197788Thanks
IFR 2399 - Page 1
Forum section: electronics / rf-microwave

author: tiredtech
author_rank: Newbie
timestamp: August 26, 2020, 04:25:36 am
content: I am looking for a MAINTENANCE manual and/or schematics for the IFR 2399 Spectrum Analyzer. I have the Operations and Programming manuals. I would prefer a PDF. I am tracing down a fault in either the Tracking Generator module (most likely), or possibly a failure in the YIG signal from the RF module feeding the TG. I do not have access to another spec analyzer at this time, especially not above the 3Ghz range. Any help/advice/half-hidden pointing fingers would be appreciated. - tiredtechUPDATE: I understand that this unit originated from LG in Korea and was rebranded by IFR. Can anyone give me any more information? A basic scouring of the internet hasn't turned up anything about LG's test equipment or any documentations. The IFR also closely resembles the LIG NEX1 NS-30, but a search for info about LIG and it's test equipments also turned up little (except for sales pitches for new equipment) Again, any help is appreciated. - tiredtech
Help with RN4870 module connecting to Linux - Page 1
Forum section: electronics / rf-microwave

author: siliconwasteland
author_rank: Newbie
timestamp: September 03, 2020, 08:57:37 pm
content: Hi,I'm working on a project that uses a Microchip RN4870 bluetooth module. I've configure the module to act as a transparent UART using a "SS,C0" command followed by a "R,1" to make it take effect. I can connect to the module using a BLE scanner app on my iPhone. I can pass text text data both directions.Now I am trying and connect and pass data from a raspberry Pi 3.In the bluez config file I add the following items and reboot:# Add Serial Port profilevi /etc/systemd/system/dbus-org.bluez.serviceExecStart=/usr/lib/bluetooth/bluetoothd -C ExecStartPost=/usr/bin/sdptool add SPI next used bluetoothctl so scan for my device and find it:# bluetoothctlAgent registered# scan onDiscovery started Controller B8:27:EB:xx:xx:xx Discovering: yes  Device 80:1F:xx:xx:xx:xx RN4870-B83F # scan off Discovery stoppedNow I pair the device and it appears to pair just fine:# pair 80:1F:xx:xx:xx:xxAttempting to pair with 80:1F:xx:xx:xx:xx  Device 80:1F:xx:xx:xx:xx Connected: yes  Device 80:1F:xx:xx:xx:xx ServicesResolved: yes  Device 80:1F:xx:xx:xx:xx Paired: yesTrust the device:[RN4870-B83F]# trust 80:1F:xx:xx:xx:xx Device 80:1F:xx:xx:xx:xx Trusted: yes Changing 80:1F:xx:xx:xx:xx trust succeeded [RN4870-B83F]#From the serial port of the RN4870 device I see the connect:%CONNECT,0,B827EB7EC9CC%%SECURED%%BONDED%Then I use rfcomm to bind to the bluetooth device and create my serial device:rfcomm bind 0 80:1F:xx:xx:xx:xx 1ls -l /dev/rfcom*crw-rw---- 1 root dialout 216, 0 Sep 3 14:44 /dev/rfcomm0When I use the show command everything appears good:rfcomm show rfcomm0rfcomm0: 80:1F:12:B5:B8:3F channel 1 cleanWhen I try and use minicom to talk to the bluetooth module using /dev/rfcomm0 I get nothing. The speed and data format are set correctly.Has anyone had any success with this module connecting to linux? I would greatly appreciate any suggestions.Cheers,len
"Dayton" national hamfest has  all speaker presentations, more till Sept 9. - Page 1
Forum section: electronics / rf-microwave

author: jh15
author_rank: Frequent Contributor
timestamp: August 25, 2020, 01:01:31 pm
content: Until Sept 9, you can attend the virtual "Dayton" hamfest starting on Aug. 8.https://qsotoday.vfairs.com/After you register, you can access all presentations and exhibits until Sept 9. I haven't seen much if any spam even though going to exhibit booths.I got way more out of this virtual hamfest than going live, except for the booth babes.I got into some now continuing chat on Discord, for example "Linux in the ham shack" and the like.After registering, click ob the big building picture, then the Auditorium clicker to get a ton of the then live presentations on many subjects.I believe there are ongoing deals with the factory exhibitors till then.It will be virtual again in the spring.73
What is Antenna Factor of 10dB VAMP9243 - Page 1
Forum section: electronics / rf-microwave

author: ornea
author_rank: Unknown
timestamp: August 23, 2020, 03:46:51 am
content: Not 100% sure what I am doingSo I have a sig gen outputing 10MHz 50dBuV/m connected to a test jig that attenuates the signal to a level measured at approx 34dBuV/m.The test jig/circuit is designed to attenuate and inject a signal into the VAMP (Active antenna).With the Vamp and test jig in circuit the level is measured at approx 20dBuV/m but we think it should be back up around 50dBuV/m.If the Vamp is powered off the signal disappears, and powering on the signal re-appears, so it looks like the Vamp is doing something, just not sure if it is amplifying correctly.So what is an antenna factor of 10dB. Can i roughly equate this to an gain of 10dB for a range of 3 - 30MHz.Any one had experience with these active antennas. Have we broken it perhaps?Justin

author: bob91343
author_rank: Super Contributor
timestamp: August 23, 2020, 06:24:13 am
content: You are using strange terminology. You can't have 50 uV/m in a circuit; that's a unit of field strength.In any case, be more careful with your technical language so it can be understood.

author: ornea
author_rank: Unknown
timestamp: August 23, 2020, 07:06:02 am
content: Thanks for the heads up, my bad, on the Rohde & Schwarz ESR - EMI test receiver I dialed up 50dBuV @ 10Mhz not 50dBuV/m. It is the EMI test set that is measuring in dBuV/m units or calculates its display to provide dBuV/m.

author: radiolistener
author_rank: Super Contributor
timestamp: August 23, 2020, 08:59:21 am
content: Do you perform antenna field measurements in the anechoic chamber?Something like this?Can you provide schema of your installation?
Philips Television Tuner history - Page 1
Forum section: electronics / rf-microwave

author: jonovid
author_rank: Super Contributor
timestamp: August 25, 2020, 10:52:59 am
content: IMO its rare to find a complete or deep look at recent history of a product not hidden behind proprietary access or paywall.lots ofRadio frequency design historyhere. if your ever interested in anything about thetechnology of television receivers.that is more then just a brief mention. you may even able to identify something you have, or seeking to re-use or repair.I have a parts bin full of old CRT television pcb's at home.fascinating history of Television RF modules over 30 years.I found this electronics post by Pieter Hooijmans and Maximus-R&D interesting. So I did link it here, enjoyquotethe 1980s and a lot of things have happened since the first tuners from the early 1950s. Television, and especially colour television, has become omni-present in the whole world, the TV is a standard consumer device in almost every household. Volumes have consequently soared to more than 100Mio sets per year, requiring massive factories. The leading players had grown bigger and bigger, often through consolidation of the smaller players, but in parallel a new set of players had emerged: the Japanese companies, especially Sony and Matsushita/Panasonic.https://www.maximus-randd.com/tv-tuner-history-pt5.htmlhttps://www.maximus-randd.com/tv-tuner-history-pt4.html#uv600

author: rfbroadband
author_rank: Unknown
timestamp: August 25, 2020, 08:03:48 pm
content: thanks for sharing. These TV tuners are the reason why I live in the US now. I joined a startup in the US and moved from Germany to the US working on a fully integrated Si TV Tuner IC (thus no tracking filters etc).Today's silicon tuner ICs are fully integrated and tracking filters that need to be hand aligned in a manufacturing line are no longer needed.I will definitely read all 5 parts. This looks like a fascinating summary. Thanks again for sharing.

author: edigi
author_rank: Regular Contributor
timestamp: August 26, 2020, 02:09:18 pm
content: This is such an excellent description of the technological and management challenges that I think one can still learn a lot from it. Big thanks for sharing it.It's a pity that the pictures don't have a larger version (that could open via clicking on them).
how to measure tx rf power output using what i have here - Page 1
Forum section: electronics / rf-microwave

author: m3vuv
author_rank: Super Contributor
timestamp: September 08, 2020, 11:08:34 am
content: Hi all,i need to be able to set my rig tx output to 10w to do some work on it,i dont have a decent power meter at the moment,i do have a marconi rf voltmeter,a 50 ohm dummy load ,a fluke 85 ,also this is just for 3.5mhz,my scope is a tek 453,how can i do this?,cheer m3vuv.

author: Grandchuck
author_rank: Super Contributor
timestamp: September 08, 2020, 11:23:46 am
content: When you have a little over 22 volts rms across the dummy load, you will be at 10 watts. This can be found by manipulating the formula:P = V^2/R

author: m3vuv
author_rank: Super Contributor
timestamp: September 08, 2020, 11:41:01 am
content: is that best measured with my scope or fluke,my rf voltmeter goes up to 3v max,do i take the peak reading and devide by 0.707?

author: Grandchuck
author_rank: Super Contributor
timestamp: September 08, 2020, 12:27:12 pm
content: The meter does not have the bandwidth needed. I don't know anything about the Marconi. The scope should be OK. Use 0.707 as a multiplier:Vrms = Vp x 0.707(Don't forget to divide Vpp by 2 to get Vp)

author: m3vuv
author_rank: Super Contributor
timestamp: September 08, 2020, 03:06:55 pm
content: many thanks for that,73 m3vuv

author: Yansi
author_rank: Super Contributor
timestamp: September 08, 2020, 03:12:57 pm
content: At 3.5 MHz and those voltages involved (22Vrms), a simple Si diode detector would work with acceptable error. A simple 1N4148 or BAV21 diode would be probably sufficient to detect the peak value; assuming a small enough distortion one could estimate the power on the load from the detected peak voltage.Do you have an oscilloscope with >> 3.5 MHz bandwidth?

author: Mechatrommer
author_rank: Super Contributor
timestamp: September 08, 2020, 03:16:42 pm
content: 3.5 milli hertz? good! just make peak detector diode and measure with just any DMM...(same advice if you meant 3.5 MHz) yeah, Yansi beat me to it...

author: TimFox
author_rank: Super Contributor
timestamp: September 09, 2020, 10:02:21 pm
content: Which Marconi voltmeter do you have? My Marconi 2610 true-rms voltmeter has a nominal bandwidth of 10 MHz. Its highest full-scale range is 700 V rms, but I would hesitate to put that much voltage on a BNC connector.I checked the specs: accuracy spec’ed to 10 MHz only up to 20 V rms full-scale.
Understanding 1:1 Ruthroff ("voltage") baluns - Page 1
Forum section: electronics / rf-microwave

author: galvanix
author_rank: Contributor
timestamp: August 14, 2020, 11:34:03 am
content: Hello,recently I've come acrossthis (PDF warning)return loss bridge by VK3DIP that uses a 1:1 Ruthroff balun to convert the differential output signal to a single ended signal that can be fed into a receiver.I'm only familiar with 1:1 "current" baluns aka common mode chokes.Looking at 4:1 voltage baluns I can see how a 4:1 balun achieves an impedance ratio of 4:1 because impedance is always voltage divided by current, however the Ruthroff style 1:1 "voltage" balun has me baffled. I just can't seem to wrap my head around how to analyze voltages and currents on this schematic (courtesy of M0UKD):I think what confuses me the most is that this is not behaving as an inductive voltage divider because all of the inductors are mutually coupled by being wound around the same core.Is there some straightforward way to understand this type of 1:1 balun?

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: August 14, 2020, 12:14:08 pm
content: Hi,Try thinking of it like this:I start with a 1:1 with a center tap on the output and then manipulate the winds to arrive the solution. It is a 1:1:1 auto-transformer.Regards,Jay_Diddy_B

author: galvanix
author_rank: Contributor
timestamp: August 15, 2020, 08:16:17 am
content: Thanks for that step-by-step redrawing of the circuit, so the center winding is essentially used as part of the primary and part of the secondary at the same time.Can the primary/secondary still be analyzed independently from each other even though they are electrically connected?

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: August 15, 2020, 12:05:44 pm
content: Hi,You can look at this several ways.1) If you remove the center section you are left with a common mode choke.2) If the load is balanced the center section only has the magnetizing current of the transformer.3) If the load is not balanced the current in the center section is the difference in the load current divided by 2.4) The center section defines the output voltage with respect to ground.Regards,Jay_Diddy_B