Ham Radio Transverters (28 to 144) - Page 1
Forum section: electronics / general

author: Flump
author_rank: Frequent Contributor
timestamp: February 13, 2015, 01:41:01 pm
content: I want to use my HF radio on 2m, I have an old broken MM Transverter butit has seen better days so I have been looking for HF to 2M Transverters andfound this board, which looks quite nice (to my inexperienced eye)I wonder if anyone here has used or know someone that uses one of these ?or what peoples opinion about it is?http://transverters-store.com/144mhz.htmhttp://www.ebay.co.uk/itm/251815870889?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

author: German_EE
author_rank: Super Contributor
timestamp: February 14, 2015, 09:18:05 am
content: From the picture the board looks OK but I am not sure about the transmit output stage. 10W-15W output from a single device normally means that they are operating the stage in Class C which means FM and CW mode only, but they do say that the unit is "all mode".Here are some other manufacturers of transverters:Down East Microwavehttp://fwfvq.tehfm.servertrust.com/category-s/1834.htmElecrafthttp://www.elecraft.com/XV/XV.htm

author: VK5RC
author_rank: Unknown
timestamp: February 14, 2015, 10:33:32 am
content: It doesn't seem super cheap esp if you allow for the additional costs of transmit receive relays, sequencer and all that other stuff. Do you have the gear to test it for harmonics etc?Elecraft gear is usually excellent.

author: Flump
author_rank: Frequent Contributor
timestamp: February 14, 2015, 10:07:34 pm
content: Hi german EEI don't have the budget for a DE or Elecraft one but I do have a CB amplifier with blown PA transistorsand it will cost more to repair that than its worth, so the plan was to remove the board and put thetransverter and attenuator boards in it.VK5RC I wasnt aware it needed TX/RX relays or a sequencer, I thought it was just a case of a suitable attenuatorand hook up the external connections to the board, the transverter has a TX connection which needs to be grounded,I was going to hook that up the my yaesu FT-950 as it has that for connection amplifiers.

author: VK5RC
author_rank: Unknown
timestamp: February 14, 2015, 11:27:10 pm
content: Hi FlumpWhen I posted I was on a mobile and couldn't get pictures of the circuit diagram, you are right, it does have silicon switching so no delay needed. Do you intend to switch out the attenuation on receive?I must admit to being a bit cautious with transverters and a nice unit like the FT 950!How does the 950 reduce power? I think the IC 706Mk2G has a nasty habit of of at the beginning of tx being at high power for a very brief period then using the ALC to de-power.

author: kc9qvl
author_rank: Regular Contributor
timestamp: February 15, 2015, 12:23:14 am
content: Hmm definitely class C amp. What HF radio would you use it with, Does it have a low level rf output? For the price might be better to get a used 2 meter mobile.

author: GreyWoolfe
author_rank: Unknown
timestamp: February 15, 2015, 04:22:48 pm
content: I am with KC9QVL on this. You have to be very careful how you feed the transverter. If you forget to reduce the radio power you will let out the magic smoke. I think your best bet would be a 2 meter mobile radio. The only radios safe for transverters are those that have the ability to automatically reduce the power when the transverter is engaged like the Yeasu FT-1000MP. Besides, the mobile radio will give more power. In the house, I typically set my Kenwood TM-281 to 25 watts output (low power setting) but it is nice to know that I have 65 watts should I need it.

author: Flump
author_rank: Frequent Contributor
timestamp: February 15, 2015, 05:38:12 pm
content: Hi All , thanks for the replies so far.I have a few radios that work on 2M, yaesu 8800 dualbander , trio 9130 and kenwood ts-711ei want to drive a transverter with my yaesu ft-950 which does not have a dedicated port for itso the plan was to built a relay switched attenuator (around 15db) so it is bypassed on RX and being hard wiredinside the unit there wouldnt be a worry of forgetting to switch on the attenuator.it's more of a project i want to do rather than a need for it.

author: VK5RC
author_rank: Unknown
timestamp: February 16, 2015, 10:37:09 am
content: @Flump One issue could be if the relay is a bit slow in opening, so no attenuator in circuit until it does and if the FT 950 gets power out very shortly after the PTT goes to ground, you might get a spike of unattenuated RF into the transverter. This is where a sequencer can help if you can get it to lower the output of the FT950 for 50mS or so.If you already have a 2m radio, could I suggest a 'microwave' 1+GHz transverter as an alternative? it will open up some new bands and the only way to get to 2+GHz is with home-brew. in the UK there are some serious microwave groups who I am sure would be willing to help if needed.I am about to try and bounce a 1.2GHz signal off the moon, I have an Icom 910 (10W) going into a 160W W6PQL PA, with sequencer et al on the transmit side and a UK hams G4DDK low noise pre-amp kit (37dB gain 0.27dB noise factor) on the receive. Planning, designing and testing is most of the fun. I have done some sun-noise tests (VK3UM has a great site for some calculators) and been able to measure it within a dB or so of that calculated.73 de Robert

author: GreyWoolfe
author_rank: Unknown
timestamp: February 16, 2015, 05:49:14 pm
content: Quote from: VK5RC on February 16, 2015, 10:37:09 amPlease post a pic of your antenna array. I like antenna porn.

author: VK5RC
author_rank: Unknown
timestamp: February 16, 2015, 08:06:19 pm
content: For a laugh;The feed horn support pole is a piece of bent exhaust pipeThe support frame for the dish is based around an engine standThe feed horn consists of a piece of stainless steel flue pipe and a cake tinThe whole assembly can be moved and stowed around the side of the house, unfortunately too many trees to be used there!

author: Howardlong
author_rank: Super Contributor
timestamp: February 16, 2015, 08:57:47 pm
content: Quote from: VK5RC on February 16, 2015, 08:06:19 pmVery nice! Interested to hear how you get on with that setup. FWIW your dish looks about the same size as G4DDK's, I've been to his place quite a few times, he works on some of the space related projects I work on. I live in a flat in the middle of London, so getting BUDs up is not on the menu regretably, but I have managed to put up a dual band feed for 23 and 13cm on a 1.2m homebrew dish for satellite, worked pretty well, until the noise floor made it barely useable due to all the unlicensed stuff on 2.4GHz coming on line in the early/mid 2000's.G6LVB

author: VK5RC
author_rank: Unknown
timestamp: February 16, 2015, 10:57:39 pm
content: QRM is the scourge of the times, cheap switch modes, poorly shielded high speed digital signals are a curse, my hf setup is now deaf as a post with s7 noise on 20m.My next issue is to try and pick up an eme beacon, if that and a self echo go well I will try a contact with vk3um (a vk eme guru).I would encourage the OP with home-brew, it's a lot of fun, you learn a lot, especially bl#&dy earth loops!

author: UT5JCW
author_rank: Newbie
timestamp: March 26, 2015, 02:06:15 pm
content: Quote from: Flump on February 13, 2015, 01:41:01 pmWe are a producer of those transverters boards. We are offering money back if you were not satisfied with a purchase. We sold a lot of these boards. All customers like them. To see my feedbacks on eBay. 73!

author: LaserSteve
author_rank: Super Contributor
timestamp: March 26, 2015, 03:05:01 pm
content: UT5JCW Is it linear for SSB?73,Steve N8KVD

author: PA0PBZ
author_rank: Super Contributor
timestamp: March 26, 2015, 03:19:40 pm
content: Looks like it is:

author: UT5JCW
author_rank: Newbie
timestamp: March 26, 2015, 07:00:22 pm
content: Quote from: LaserSteve on March 26, 2015, 03:05:01 pmYES it is and there you find a pot to change the bias.

author: XFDDesign
author_rank: Frequent Contributor
timestamp: March 26, 2015, 11:21:08 pm
content: The fact you got an RD15HVF1 to work without singing itself to death is impressive. RD16HHF1s? No problem. RD15s? Laaaaaaa<poof>

author: UT5JCW
author_rank: Newbie
timestamp: March 27, 2015, 03:16:32 am
content: What you mean? It works fine. It is very durable. Both of them works equal. Getting 10-15 watts easy.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 27, 2015, 03:41:59 am
content: Quote from: XFDDesign on March 26, 2015, 11:21:08 pmHmmm... looking at the datasheet, they give S-params up to ~GHz, not that there's any gain left up there... but of note... the phase angles arenegativeover a generous stretch of that range!TO-220 is NOT A GOOD PACKAGE for this kind of device...Tim

author: Richard Head
author_rank: Frequent Contributor
timestamp: March 27, 2015, 06:14:15 am
content: TimThe package has different pinouts compared to a switching MOSFET. The Source is the centre pin and tab so you can easily ground the tab to the heatsink.The Mitsubishi MOSFETs are not actually intended for linear operation (check datasheet) but give reasonable SSB performance if backed off quite a bit.You'll notice that none of the datasheets of the RD range mentions its IMD performance.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 27, 2015, 02:49:15 pm
content: Quote from: Richard Head on March 27, 2015, 06:14:15 amThat's all well and good, but my point was, the S params are largelynegativein magnitude...If such a beast is more stable in class C, I suppose that's something. (Who cares if it oscillates, as long as it oscillates at the desired frequency?)Tim

author: XFDDesign
author_rank: Frequent Contributor
timestamp: March 27, 2015, 11:37:58 pm
content: Quote from: T3sl4co1l on March 27, 2015, 02:49:15 pmThe RD series are usually pretty linear (for FETs), and I'm pretty successful with the RD16 for my linear Class A/Class AB designs. Every time I try to build with a '15 though, it sings at some high frequency until it burns up. :|The RD01MUS1s are a bit fussy, but I'm able to tame them okay.

author: G8EKG
author_rank: Newbie
timestamp: May 30, 2016, 08:27:54 pm
content: I have actually bought 2 of these transverters. The first one I damaged while mounting in a diecast box. The second seems to be working OK. Be VERY careful with drive power they are easily popped! As far as linearity is concerned all I can say is if they're not overdiven IMD is as good as my DEMI 144/28. Of course with such a basic design don't expect the performance of a $1300 Kuhne. If I were you I'd fix my ancient MM transverter. I still use one on 70cm and it's bombproof! These are still very well respected. Just check the Ebay prices.73Geoff

author: serge_m
author_rank: Newbie
timestamp: May 24, 2017, 02:07:32 pm
content: Quote from: UT5JCW on March 26, 2015, 02:06:15 pmActually no. You are just seller. Real author and producer of transverters from your store is Alex UR3LMZ ashatun@mail.ruAnd now you stole almost all of his transverters and started producing yourself.To the community - please contact Alex UR3LMZ directly if you have any questions related to the transverters as nobody knows the devices better then the author. Be informed that original transverters boards do not have silkscreen.

author: PA0PBZ
author_rank: Super Contributor
timestamp: May 24, 2017, 02:54:26 pm
content: Quote from: serge_m on May 24, 2017, 02:07:32 pmSo actually he is the producer, just not the designer...

author: serge_m
author_rank: Newbie
timestamp: May 24, 2017, 02:59:59 pm
content: Starting from now he produces transverters 50/28, 70/28, 144/28, 222/28 without acception from the author. In 2015 (when he wrote the message) he was just reseller.Here is the source -http://www.cqham.ru/forum/showthread.php?29083-%CF%EE%F1%EE%E2%E5%F2%F3%E9%F2%E5-%F2%F0%E0%ED%F1%E2%E5%F0%F2%E5%F0-%F1-28-%ED%E0-144-430

author: f5dqk
author_rank: Newbie
timestamp: November 22, 2017, 02:16:30 pm
content: Searching different articles on the net concerning UT5JCW transverters meases (and particularly the 432 to 28 MHz one), did anybody make real gain/Nf meases (principally Nf) of the total Rx conversion with an NGA (Eaton 2075 or HP8970) ? ? ?Because I didn't find ansolutely nothing about ! ! !And more said, did anybody look at the great meas differences obtained between his 3 versions N-2 (with relay + diode mixer), then N-1 or actual N models (with PIN diode switching) ? ?UT5JCW says that he measures every transverter before shipping, and that in every case the Nf will be less than 1dB.I did a complete study on it with an another french ham very known as RF measuring specialist.So I want anybody to exchange about this important subject (and also for every 50, 70, 144, 22 or 432 MHz family, also via direct mail)Before buying specifically the 28/432 MHz model (exactly 3 successive generations), have a little look at its RF Tx and Rx measurements posted on !http://f1chf.free.fr/F5DQK/6_Transverters/Transverter%2028_432%20MHz%20UT5JCW.pdfand also herehttps://f6kmx.fr/technique/transverter/etude-du-transverter-28-432-mhz-ut5jcw-par-marcel-f5dqkThank you for looking ! ! !