Funny that the SSCPO topic should crop up. I just finished a little surface mount version of Dave's circuit. Decreasing the value of the resistors in series with the speaker and it performs quite nice

Update: it's amazing what you can learn just by "doing your homework" :^)) Scott (N3FJP) has in fact already implemented an "almost as good" feature for sending CW over the CAT connection to the Elecr

I should append a note about using the keying interface with rigs other than the K2... The 4N25 optoisolator's output transistor is rated at 70 volts C-E breakdown and 50 mA continuous collector curre

A few days ago I was reading Terry's (WA0ITP) description of a keying interface he made in order to use N3FJP contest and general logging software to send CW . His interface connected to a PC's printe

If you should choose to go with a higher voltage battery with a regulator, take a look at this adjustable regulator/current limiter project, that was in CQ back in Feb of 2018 (I think) : https://qsl.

Another for your fireside reading - quite a few references to ham operators helping in 1940s electronics development: It's a story of the development of the proximity fuse: 12 Seconds of Silence by Ja

Hi Gang, About two weeks ago Gloria (WD5CMA) and I had a chance to spend a week at our son (W5WWX) and daughter-in-law's cabin the the north Georgia mountains (Blue Ridge GA) inside the Chatahoochee N

Posted also to the Bayou Jumper Group: Another book to add to your fireside reading list: Scholars of Mayhem, by Daniel Guiet and Timothy Smith ISBN 9780735225206 (hardcover) or 9780735225213 (ebook)

will try to check in on 40 m with the prototype Bayou Jumper... be sure to listen down a bit... my xtal is 7121.7 Jim, N5IB

Hi again Dave, Look and see if the Nano has an option to display the reactive part as ohms instead of capacitor/inductor units. That'll make it much easier to interpret. For example - in your 30 m mea

Now, no one ever made a QSO with a computer model of an antenna, but software like 4NEC2 can be useful to gain some insights. Here's an attached simulated sweep from 80m to 10m of Dave's 72 ft wire. T

Go a step further with your Nano. After getting the swr data, also get the impedance information (R +/- jX). You may find one case of high swr involves a fairly low impedance, while another case is as

BTW ... of interest to many... There is a simulator of the T network tuner at: http://fermi.la.asu.edu/w9cf/tuner/tuner.html It's a great way to practice adjusting the beast without smoking too many f

Hi Dave, I looks like something is working as it should... but the trouble with that test is you're still testing two things at once - the bridge part and the tuner part. You need to isolate the funct

Dave (NM0S..... get ready to chime in here... I'm going to risk violating Mark Twain's advice ("keep silent and be thought a fool, or speak and remove all doubt) ... and try to explain the workings of

Hi Dave, First thing to do is determine if the problem is with the SWR bridge part or the tuner part. Unfortunately with this circuit you can' t test the just the bridge into a dummy load without havi

Congrats, Herb! Good catch. As a fan of the British mysteries, I love a good detective story where the perpetrator is discovered by good old fashioned sleuthing. Let the evidence point the way. BTW -

Hi Herb, I'm presuming you've fixed the earlier problem of low voltage on the Q3 collector? Before replacing any more parts, do a little voltage detective work for us. This will give some clues as to

This is a good excuse to do a little engineer/detective work involving the schematic and the data sheet. The schematic shows that the Source of Q2 is to be connected to the ungrounded side of R8. The

I'll share a little article I wrote for our club newsletter a few years ago PDF attached .... if I did it right :^)) Jim, N5IB