TR-35 group/forum

[KB4VU]

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

[kx9rt]

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

[KQ4EHE]

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

[KL7MJ]

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

[k8zfj]

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

[KL7MJ]

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