For soldering magnet wire, I purchased one of these tools: https://www.amazon.com/gp/product/B003RWS8XE/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 to pre-scrape the enamel from the wire before

When running my Pi 4 from a user account, I had to: sudo adduser <my_user_account_name> audio and sudo adduser <my_user_account_name> dialout before I could connect to my QDX.

Thanks for the suggestions. It sounds like I am hosed. IC1 is showing 5V input and 3.3V output. I didn't dare to try to measure voltage on IC8, but I do have continuity from the 3.3V rail to a

Mmm, it appears I got something quite similar after finishing the build today. QDX build for 12V, firmware 1.04 . - Current consumption: 173 mA - Low audio level in WSJTX, only ~ 10 dB above

On Mon, Aug 1, 2022 at 04:23 PM, Andy G0FTD wrote: On Mon, Aug 1, 2022 at 03:52 PM, John Rabson wrote: I seem to recall a question in my IEE (1966?) fiinals which asked me to outline the design of a

Thanks Dan! 73 Hans G0UPL http://qrp-labs.com https://www.buymeacoffee.com/g0upl

Dave, you seem to be getting Exactly the same results as me. rx current 180mA, low audio out (btw, mic input is wrong input for wsjt-x - select qdx ip and op), poor LSB separation. When you have

I personally have not had good success with the burning the insulation off method. I find I have much better results using an Exacto blade to scrape off the enamel from magnet wire. Yes it's more time

By the way, my current draw readings are from my bench power supply so may not be that accurate. After running the radio for a couple of hours and making several QSO's, nothing got too hot (apart from

** Update ** In the interests of sharing my findings, I have now got it working. What I have done: - Reworked L12 - this improved things greatly ( I must have had a fault there). - Reflowed joints on

My experience is on QCX+ rather than QDX but for what its worth : Having put a very very light smear of heatsink compound (standard white silicone/zinc stuff) on the flat faces that get screwed to

Mike Ah yes! I too remember now. Hans did say somewhere that the different audio ICs in the v3 took more current. If Dave's measurement is accurate his is taking a little more than normal. But not a

On Mon, Aug 1, 2022 at 03:52 PM, John Rabson wrote: I seem to recall a question in my IEE (1966?) fiinals which asked me to outline the design of a 1kW transistor AF amplifier. I asked a neighbour who

I think the 100ma RX current value was from early QDX history and with the various upgrades most recent builds have been averaging out in the 140-150 ma range. I believe there was a note to this

We hear about all the problems on here, so I thought I'd post something positive. I recently installed updated 1.08 firmware chips for my original QCX 40 & 20m and QCX mini 30 & 60m. The minis have

I seem to recall a question in my IEE (1966?) fiinals which asked me to outline the design of a 1kW transistor AF amplifier. I asked a neighbour who worked in semiconductor research if the examiners

Dave, This test shows if T2 is wound and installed correctly. How much down is LSB? If it is around possibly 50dBthen the secondaries must be wound and connected correctly. Fundamentally there is no

Yep: https://www.mouser.com/new/nxp-semiconductors/nxp-mrf1k50h-transistor/ As used in the Elecraft KPA-1500 (two of them, which gives a great deal of overhead). And I do have CK-722's. They came in

Jason, The next step would be to verify IC1. It should have 5volts on the input and 3.3volts on the output. A correct input and no output would mean a bad IC1. I am using the fact that the current