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A short in your keyer wire/plug? Dwight C Watson Dwatson4@...

I see a number of topics addressing various issues with the Keyer but after trying all the various solutions I can't seem to solve mine. I have a MFJ-564b that seems to work flawlessly on my Elecraft

The TLC272 is not a rail-to-rail capable op amp and can only supply 10mA. So it's not a full replacement for the TS922, though it may suffice in this application. The TLV272 is rail-to-rail but can

Hi Jim We post 600-800 packages per month. A lot of money! 73 Hans G0UPL http://qrp-labs.com

I think TLC272 should also do the job, except perhaps for the final headphone stage. It's a similarly specced part, and is available in DIP. Regarding the supply voltage, look at the lowermost right

You are correct: the TS922 is now only available in SMD packages. You would either have to find some NOS DIPs or use an SOIC to DIP adapter. The other alternative is to find another suitable part. So

To get the best power output from QCX. --- This email has been checked for viruses by AVG. https://www.avg.com

I've made progress but it still isn't working right. I rewired T1 and reinstalled it. That fixed the loud tone but I caused more problems. I lifted a trace off the board from pin 4 of T1. It appears

There's some great advice in this thread and replacing IC6-9 sounds like a worthwhile mod, but I'm having a bit of trouble sourcing the TS922 in a DIP8 package.? They seem to have been discontinued

Great job on this video again Juddie with that CW switch plunger.? I did the same with mine, but I made my own plunger mod similar to yours.? I am interested now, in your "tilt up" stand that I can

I do not know if it helps, but I have encountered all sorts of resets ,frequency shift and blocking LCD with VFO signal generator transformed into TX WSPR in 28 and 14 Mhz. Now I'm feeding the three

Hi Alan, Academic?? ALL failures are an opportunity to learn and make a product more robust. I am surprised no one has talked about bringing up the power in steps? Measuring things as we go up to full

Hi Glenn, I'm in defence of all Hans views as well. /g/QRPLabs/message/26421 (I keep pointing out his statement that he has never experienced a failure of any prototypes and beyond to

Oops, sorry.? I meant Jim, not Ted? :-) 72 de Gary W0ITT

Ted - I had a similar experience.? Be sure you are using a stereo plug in the key jack.? The QCX *requires* one.? If you put in a mono plug it just keys the transmitter, and the tone you hear may

In defense of Hans, I don't recall seeing a brag about QCX able to handle infinite-SWR conditions. (ie: antenna short or open-circuit). ?I can see a dangerous scenario.... if you're using an

Hello Allison and Hans Many thanks for the detailed reply, I will take on board both yours and Hans' advice, much appreciated! Friday, August 24, 2018

The practice test was negative. My mistake: My tuner tunes to antenna voltage, no control of adaptation to the PA. This caused the PA to overload, causing the MPS2907 to burn. Repair ok. Change tuner

Alan, I don't know how Hans had no trouble although it could be that most QCX do survive abuse. Maybe only a few actually have problems? The design here

The LDG Z-100Plus requires only 0.1 watt to tune according to LDG and is rated for 125 watts which leads me to think that it has lower losses than some of the "QRP" tuners with much lower ratings.