¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io
Re: Oscillations on high bands
Testing my 20W PA with -10dB in verses? 0dB in I see very little change in gain on lower bands 160-7, some gain on 10-17 and significant (3dB) gain on 28-50 Mhz. Max 0dB in is 160-80m is 12W,?
By Tim · #33304 ·
Re: Need HELP!!!!
to avoid misunderstandings: 3.3V are only on pin46 with teensy in! Teensy produce this 3.3V by himself! we have ?different rails with 3.3V!
By Ralph Lieber · #33303 ·
Re: Need HELP!!!!
if there is no 3.3V on Pin46, please check for short (without teensy) pin46 to ground! if there is a short you will destroy the (next) teensy if you (re)placed him!
By Ralph Lieber · #33302 ·
QRP-Labs
I was just browsing their website, and I noted that Hans has finally released beta SSB software for the QMX. Downloaded it, ran it...holy crap, it works! SSB is created by doing magic with the IQ
By jerry-KF6VB · #33301 ·
Display driver board
I sent out five of those new display driver boards about a week ago and only saw posted that Terrance got his working as was able to use a 3-foot long display cable without display-T41 errors/lockups.
By K9HZ · #33300 ·
Re: Need HELP!!!!
If no voltage on pin46 then the teensy socket or teensy itself is bad. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch ¨C K9ZC Staunton,
By K9HZ · #33299 ·
Re: Need HELP!!!!
D2 and D3 are illuminated? If so the power rails are working. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois
By K9HZ · #33298 ·
Re: Need HELP!!!!
Thanks for the advice. Here's what I have done so far. 1. Replaced the LM117 2. J5- 3v and 5V on their pins 3. 5v on TP1 4. 3.3v on TP2 5. 12v on Fan port 6. Replace the pin connector for the teensy
By Tom Schulte · #33297 ·
Re: Need HELP!!!!
1) I would take out the teensy (socketed ? and possible?) and would check the TP?s like Oliver 2) if it?s ok 4 possibilities a) Teensy is defekt b) check Teensy Pin 46 (without Teensy) is there a
By Ralph Lieber · #33296 ·
Re: Oscillations on high bands
Here's the gain of my K9HZ 20W PA: If we calculate the gap between the feedback amplitude and the amplifier gain, we can quantify how much margin we have before the radio begins to oscillate. It's a
By Oliver KI3P · #33295 ·
Re: Need HELP!!!!
I had a Teensy blow when on power up because a the LM1117 failed. I replace the LM1117 with MP2307 buck converter module. The LM1117 had the fan and heatsink on it but its current rating is
By JerryP · #33294 ·
Re: Oscillations on high bands
Good detective work. That should do it. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois Owner ¨C Operator
By K9HZ · #33293 ·
Re: Oscillations on high bands
I have now confirmed that, after I replaced U8, the latest version of the code (Ver66-9) on GitHub ( https://github.com/KI3P/SDTVer066-9 ) does not suffer from oscillations on any band with my V12
By Oliver KI3P · #33292 ·
Re: Need HELP!!!!
Also don't forget you have to slice the trace on the Teensy to disconnect the USB power. -- 73 Greg KF5N
By Greg KF5N · #33291 ·
Re: Need HELP!!!!
Do you know how your Teensy got blown? That shouldn't happen. Before placing your Teensy on the board, power it up and check that the DC voltages are correct. The schematic is here:
By Oliver KI3P · #33290 ·
Re: Oscillations on high bands
I discovered that U8 (an RF switch) was not working on my LPF board. It provided very little isolation. I measured this by removing the LPF control board from my radio and testing it a NanoVNA and the
By Oliver KI3P · #33289 ·
Re: boards and kits and stuff
Great Terrance, thanks for the post. I hope others results will be good too. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch ¨C K9ZC
By K9HZ · #33288 ·
Re: boards and kits and stuff
I can report success with Bill's display driver board and also a caution.? I accidentally connected the display driver board to the Main board offset by one row and blew the MISO line.? Bodging that
By Terrance Robertson, KN6ZDE · #33287 ·
Need HELP!!!!
I have a major problem with the main board. I built it with the reverse power protection. When I first built it I had 3.3vand5v at the test points. Now when I added the teensy and audio hat and test
By Tom Schulte · #33286 ·
Re: Oscillations on high bands
Interesting, Jerry. If you have time, could you measure isolation from J8 to J7 with key down in CW, and PTT engaged in SSB, with your current SW version? dave
By D Solt · #33285 ·