Hi Martin, I have done a similar mod to two U3 receivers I have. I connected the relay drive to the spare switch on the front panel so now I have a USB/LSB select, which I use for listening to voice

Hi Adrian, I too have low Pout- about 1W- and started to do some troubleshooting. I did find my rx problem... a resistor and capacitor I somehow got in the wrong places in the 200 Hz filter area.

Hi Glen, Alan, Unfortunately Glen changed the thread title so harder to follow history and thinking, As I understood from the original thread I replied to, as built, Glen originally had .25v at at

Hi Glenn, I wonder if you have tried this beta file yet. I had a few strange issues but mainly because with setting the AUX number on the WSPR mode screens and wondered if you had the same? 73 Ken

Hi Alex well, the article states that a French translation is available, on request. I believe it can be done in English as well, worth to ask ... 73 de F5IHN

Liam, I'd look at R35, is there 5V on the end away from IC9? Are the joints sound? My theory on opamps is shaky but I'd say oscillation is unlikely. 73 Alan G4ZFQ

Glen, This does not seem to be a valid test to me. 2.5 volts is fed to IC4 via R2/1, without this voltage you probably would get a low voltage on pins 7/9. More importantly what are the voltages with

Hi David, thanks for sharing the AGC circuit. Is there a English translation available? vy 73 de Alex, DK4FT_

Thanks to Glen Leinweber's suggestion to measure the ICs DC voltages, this time comparing them with the QCX receiver receiving and with the receiver not feeding the earphones with anything, ground has

Before winding, examine the PCB to see where the ends are mounted. To wind the correct way: 1. Holding the toroid in left hand, pull a short end of wire back to front through the hole. 2.

Group. Removed S1 and S2. Have 2.55 volts at the intersection. Measure .8 volts at 7 and 9 of IC4 with no connection to S1 and S2. Can anyone verify if this is a correct reading. I want to be sure

Richard, Close visual inspection did not turn up any solder bridges or bad connections, unfortunately. R15 and R16 are the correct values. IC6, pin 5: 1.33v IC6, pin 6: 1.43v Putting the negative DVM

Thanks Dave, HiFER's are on 13.553-13.567 MHz . Most are close to 13.555 MHz. Quite active in the summer months when propagation is better. The best resource for info on them and LowFER's is the

No Ryuji, I don't think so. From the first moment I made transmissions the sidetone was far from smooth. So I changed C22 to 0,1uF. That had effect but not what I expected, so I switched to Semi QSK

Wolfgang, et al: Does this symptom kick in *after* very first transmission? Is Q6 turned off before that? If so, it is probably because of the RF flowing back into the collector/base against the

I also have low output on 30m. I'm getting about 2 watts out with 12v, and this is after playing with the windings on L1, L2 and L3. I was getting 1.5w before. I think I removed 2 turns on L3 that

Hi George. I've replied to you post off-line with a source for parts in BC. -- 73, Rick VE7TK

Hi Phil I believe you meant R39 and not R59, to be replaced by the zener diode ? I tried. However, like Wolfgang mods, I see an improvement but only at high audio level. Below mid level, the thumb

Hi, QRP Labs sell replacement packs: http://shop.qrp-labs.com/trimmer Strangely enough, the search for cheap trimmers after I ran out of Vishay ones lead me to order a QCX :) -- 73, M6XTG

Pondering over such things like propagation is a fascinating activity. Among other things that I play around with, I monitor (currently) WWV on 15 MHz using QRSS like techniques (long integration