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Discussion in 'Amplifiers' started by 619 Cheshire Cat, Apr 4, 2009.
You will need to trace the relay circuit and find voltage entering in along at some point that is keying the relay on. Something is giving it voltage when it isn't supposed to get it - obviously. With a voltmeter and a soldering iron, isolating each part and eliminating one by one will expose the problem - but it will be time-consuming and effective.
Other than that, someone else that experience with that unit will have to point out where in particular to look for the problem source...
Was it converted before purchase?
[SIZE=+2]Texas Star CW Transmitter To RF Amplifier Conversion[/SIZE]
[SIZE=+3]Model DX250 & DX350[/SIZE]
[SIZE=+1]Remove yellow 2200K cap of the oscillator board from the PCB [/SIZE]
[SIZE=+1]Remove red wire of oscillator board from RF choke[/SIZE]
[SIZE=+1]Remove green wire of oscillator board and attached 33pf cap[/SIZE]
[SIZE=+1]Solder the leg of 15 or 18pf cap to input trace on PCB[/SIZE]
[SIZE=+1]Remove black wire of oscillator board from keying jack[/SIZE]
[SIZE=+1]Remove oscillator board[/SIZE]
[SIZE=+1]Locate jumper wire attached to backside of red switch[/SIZE]
[SIZE=+1]Unsolder the ground end of jumper wire closest to the relay[/SIZE]
[SIZE=+1]Solder this end to bare lead of 10-ohm resistor behind red switch[/SIZE]
[SIZE=+1]Remove 10-ohm resistor piggy-backed to 15K resistor located next to the white sand block resistor and RF choke[/SIZE]
Was this work done prior to your purchase?
This may be a stock CW transmitter and not setup yet to work as an amplifier. I found this info on-line so not sure if it 100% correct.
All the Best
Yep I saw those instructions also. It seems that my amp was successfully converted. It matches up to the instructions here. A few people had mentioned it may have a bad keying transistor, so I'm going to change it tomorrow and see what happens!
Then it would'nt be (cbing) now would it?
The relay is seeing a path to ground on the coil so most likely the transistor has gone short and is easily replaced with minor soldering skills.
i know i could fix it, and it sounds like you can too, but,....... what about the NEXT person that does buisness with the same seller? they may or may not know a diode from a dohickey.
if you paid for a working unit, then the seller needs to understand that they need to stand behind it.
You can put 18 volts to that dave made. But the texas star won't last long at 18 volts.
It's not a phenomenon, it's physics. You have much to learn about your DaveMade.
Why buy a muscle car and run bald tires?