Re: need help

Donald Kelly

I agree with you, Cliff. It is likely a simple fix as you suggest.

Dennis, if you can't find the problem send it to me and I will look at it for you.

Edmond, OK

--- In, "KU4GW Cliff" <cliffku4gw@...> wrote:

He may not have hurt it at all Don. I built one last summer and accidentally hooked the coax jumper from the rig to the antenna in jack by mistake and transmitted on it several times before noticing and afterward mine would not tune either. I brought it home and pulled the cover off to test the parts, with checking the diode in mind as the first thing to check,, and when I opened it up one of the leads to the center coax connector had come loose. I resoldered it with a better connection and it's been working like a champ ever since then! One thing about it is if you do accidentally hook it up wrong like I did you have to keep in mind your only putting 5 watts into it which isn't likely to damage it unless you stay keyed up for a extended period of time and heat things up a bit. Good luck Dennis!

Very 73,
Cliff - KU4GW

--- In, "Donald Kelly" <DKELLY42@> wrote:


There isn't much to this circuit. You should be able to check most of the
unit with a simple bench meter with resistance and continuity. There are
four 100 ohm resistors, a 1k ohm resistor, a silicon diode, one toroid, two
Polyvaricons and I believe a 500pf capacitor.

To me the likely culprit is the diode. The little brown glassy thing.

The switches seem to be pretty hardy. It is hard to burn up a toroid.

If you have a meter check the resistors. You can detach the diode and check
resistance - extremely high in one direction and low in the other.

If your meter (I assume you have one) has a continuity checker you can check
to see if a switch contact is burned out.


From: [] On Behalf Of Dg
Sent: Saturday, April 06, 2013 2:39 PM
Subject: [4sqrp] need help

after finding the bad connecter ends on my 100 ft feed line.. it works like
a champ.. however: the zm2au tuner I bought last spring wont load at all.

I fear I fried the tuned circuit..

who would like to look it over and see if theres a problem? so we can repair
it and use it..great tuner with the 5 watt qrp rig I use.. no need for a swr
bridge..the dummy light goes off its tuned flat lol.. if i'd had a bridge
though I wouldn't have fried the circuit right? :)

Dennis wd9dwe

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