Brent builds the Penntek TR-35 transceiver kit

Many thanks to Brent (VA3YG) who writes:

Good morning Thomas, from wintry southwestern Ontario.

I thought I would send you a quick message to share my experiences, so far, with the little TR-35.

Yesterday, around 3pm, I took the above unassembled kit off the shelf and began to melt solder. The smoke test was successfully performed the next morning at 1:30am, after non-stop building (with the exception of a few hours for eating and catching up on a little tv). I measure twice and solder once hihi.

I ordered the kit a few weeks back from John Dillon, WA3RNC, and it arrived quickly by courier and all in one piece. John has super customer service and knows how to pack for delivery.

The instructions and the build went good with no surprises. Everything fit and worked as it should. The parts are all sorted and clearly labelled in a plastic sleeve and arranged in the order of assembly. Plus, a big bonus…… the toroids for the TR-35 are already wound and the ends tinned. ??

So far, I’m super impressed with this QRP rig! 40/30/20/17 meters with narrow and wide CW. 9.5vdc – 14.5vdc power requirements. Built in keyer, variable RF output to 5+ watts, (depending on the power source), RIT, low battery voltage warning, separate jacks for a straight key or paddles. After the smoke test last night, I was powering the rig with a 9-10vdc LifePO4, 3AH battery; I was able to get a solid 5 watts output. I backed off the RF pot to max out at 3 watts for 9.8vdc. A 12 vdc Life battery yielded 5+ watts output.

I’ve previously built an Elecraft K2, K1, a Hendricks PFR-3B, some Norcals, a TenTec 1340, some sweet little MFJ Cubs, QCX and QCX minis and I would have to say the quality of this TR-35 build is getting pretty close to Elecraft. I put Elecraft at the indisputable top of the heap in terms of quality, build manual instructions and customer service. Elecraft still has that stellar customer service/backup.

[…]In retrospect, it was a very satisfying build. Didn’t take a long time, parts were excellent quality, build/operating manual was printed out and included and there was no laborious testing and calibrating at the end. Calibrations and adjusting was simple.

The top nine lines [of this RBN screen] represent the first transmissions with the new rig today. 9.8vdc battery, 3 watts output into a 43’ gm vertical with 30 radials. Looks promising based on the RBN feedback…..

Time will tell how it performs in the field….. I have an idea it won’t disappoint.

72 fer nw,
de Brent VA3YG

Thank you so much for sharing this, Brent! I can tell you that you won’t be disappointed withe the TR-35’s performance. WA3RNC sent me a pre-assembled unit on loan for review and, I must say, it’s a fun and effective little radio.

Note, too, that my buddy John (AE5X) has been having a ball with his TR-35. He took it out with the big guns in the ARRL DX Contest this weekend, and he’s checked it out on the scope. John says he may have a full write-up on the TR-35 with photos as early as tomorrow. Click here to check his blog

I’ve been eyeing the TR-45 and may very well jump on one of those kits when available. 

Again, many thanks for sharing your experience, Brent!

10 thoughts on “Brent builds the Penntek TR-35 transceiver kit”

  1. VA3YG: I like those paddles!

    Thomas, thanks for what may be the first TR-35 to TR-35 QSO yesterday. After leaving the park, I returned home and resumed the DX contest. So far, 51 DXCC entities with the TR-35 at 5 watts into a dipole.


  2. nice article! i purchased mine fully assembled due to an accident that left my fingers and hands severely burned, so kit building is definitely in my rearview mirror. i too found the tr-35 to be a fine radio and for the price, a great value as well. i’m looking forward to several sota and pota activations in 2022, and hopefully thomas will put them on the website, which is also top shelf. 73! randy

    1. Congrats on your new rig Randy; I agree it is a fine radio. I’ve been playing with it all day at home. No portable ops here for a couple months anyway….. just too much snow and too cold for these old bones. This little rig seems to work real good with my small Bioenno 9vdc 3AH Life battery. When charged, the battery is about 10.2 vdc and it’s been operating at 9.9 vdc all afternoon. That voltage is nice and easy on the finals. A solid 3 watts output and lots of 579 signal reports and a little better too. Running it into a 43′ vertical antenna with 30 radials and using an LDG Z817 tuner. When portable, the antenna will be resonant wires. Looking forward to hearing about your Sota and Pota activations! 72 Brent

  3. Thomas, are you going to be at Four Days in May this year? I’m hoping to get to the vendor evening if I can get to Dayton in time.

    1. Hi, Dirk,

      I’m not entirely sure yet. I am hoping to make it to Dayton for sure–barring anything unexpected–but I’m not yet sure about FDIM.


  4. I bought one after seeing your initial impression video (and because the QCX mini was months out on backorder). This was the first transceiver build I have done and I’ll have to say, I was very impressed by how well organized the instructions and the parts strips come. The QCX Mini showed up a week or so later and I decided to build this one first because the steps seem much clearer. I was a bit nervous since I have had some kit failures that I have still not gotten to the the bottom of and the TR-35 is a lot more complex. It took me about 3 days start to finish in order to find time during busy life. The final testing gave me some grief until I realized that all the fuses in my several multimeters, lessons learned. I was nervous on the first power up but to my delight it works great! Still letting it burn in but i plan to get out and attempt some contacts this weekend.

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