The QRPer Board

Hi Brian,
Thanks for the reply. Wow, right there on the first page of the manual. Thank goodness for this forum for dummies like me who don't read the manuals. This was a fun build and even more fun to use in POTA activations interfaced with my Qrp Works Sidekar Extreme for logging contacts.
I have a few more qrp rigs but the TR35 is second only to my KX3.

Thanks again Brian.
73's Frank KB4VU

I just ran across this thread looking for a discussion on the TR-35. I received and built mine this past month. The build went great and very happy with the features as already highlighted in previous posts. There are a number of quirks and opportunities for improvement though.

- The volume is VERY VERY loud. I tried various headphones with similar results realizing that different phones have different sensitivities. The useable range is maybe the first 10% rotation of the knob with my headphone and antenna setup. A strong signal likely could cause hearing damage. I modified in the resistor divider R2 on the audio amp input (~200k fixed resistor instead of the 1k).

- AGC distorts on strong signals. Understood this is basic rig and has limitations of controlling IF gain. Remedied by twiddling with the RF gain. The Elecraft K1 uses a similar AGC circuit, but I don't recall that rig saturating was easily.

- Sidetone level adjustment not very effective. Varying the pot doesn't change the level much. It took a little fiddling to get it to a low enough comfortable level, otherwise it can be tiring on the ears in longer sessions.

- QSK not adjustable. Maybe not a quirk and is as designed. I like semi-QSK, but full QSK can be tiring in a busy/noisy band. It would be great to hear ideas on how to create a modification for this. Without access to updating the firmware one of the control lines on the micro-controller, the next option is a HW update. I tried a shorting FET on the RX input with a RC time delay on the GATE controlled by the TR signal(configured for about 200ms). The controlled delay worked very well and matched a SPICE simulation I created, but the RX sensitivity was significantly impacted. I backed out the mod and will consider it another day with maybe a PIN diode circuit in the RX path.

72,

Scott

I ordered my TR-35 kit yesterday, I'm looking forward to reduced back and shoulder pain, saved expenses on Aleeve. The more I operate CW, the less I want to bother with phone, the less I want to carry a radio that does a bazillion things I only use 1/10 of.

Cut weight, make up for it in s n a c k s

I know that this thread has been dormant for a while, but after Thomas announced that WA3RNC was shutting down his operation I hurried over and bought a TR35 kit. I'm looking forward to building it and taking it out for POTA activations this spring.

Is there a TR35 or Penntek mailing list? I couldn't find anything on groups.io.

I think I want to make the stereo output mod when I build the kit - has anyone made this mod and decided it was not the best solution later?

I've read about setting the sidetone level before closing up the rig. Assuming I set it relatively low, is there a need to adjust the level in day-to-day operations? Is there a mod, like a access hole in the side of the case that would make it easier to adjust?

Thanks, and I'm looking forward to joining the ranks of TR35 operators!

73,
Mike, KL7MJ

hi Mike.
I put small hole in mine, tho rarely re adjust it. it's the only pota rig ive used to date but like u ordered the 45 skinny after reading bout his retirement
72s

Thanks. I’m planning to set it relatively low. My trusdx rigs’ sidetone is tied to the overall volume, so when I turn up the volume to dig out a weak signal the Sidetone is painful!

73,
Mike, KL7MJ