Folks,
I would like to thank each and every one of you for taking the time to help
me out.
I finally found the problem and fixed it.
Somehow, the multimeter and my amp keying cable caused a transistor in the
IF board(
the one that times the Relay, transmit and receive mode signals from the
processor) to short. There
was a resistor that was in the circuit to prevent this from happening. But
it stayed
alive long enough to kill the transistor. The person who did the mod used a
1/4 W , where a 1/6W is
the suggested rating.
So after the transistor & resistor were replaced, the rig works fine. I
still have an issue with the
internal tuner. This should be a similar problem.
I built another amp keying cable and now the TS-440 is keying my TL-922A
just fine. I have some
questions on the right tune up procedure, standby mode indicator lamp
replacement, ON/OFF switch
replacement. I will first search the archives and then post a request if
necessary.
Its so gratifying to find and fix the problem. Its fun.
73's
krish
w4/vu2vku
krishna wrote:
> Hi all,
> First i would like to thank you all for helping me make a decision
> about
> the TL-922A.
>
> I am a happy camper. I bought the TL-922A for $675. It was amazingly
> clean for its age. I was even more surprised, since the seller
> appraised it to be of average condition. But it tuned out to be
> quite clean. I opened it up and no burns around the bandswitch.
> The tubes are clean. The previous owner was only driving it
> to about 600mA plate current. Looks like the amp was well taken care
> of before he moved to a nice ALPHA.
>
> I also got a pair of Eimac's as a backup( though not full emission).
> In short, i have a complete QRO package now. :)
>
> Now here is the sad part of the story.
>
> Not being able to suppress the urge to put things together,
> I started messing up with my perfectly working TS-440. My
> one and only radio.
>
> The users manual requires one to setup the jumper to enable the remote
> option for keying the linear. I did so.
>
> The manual has a diagram of the7-pin remote connector. I bought a 7-pin
> DIN
> connector and soldered wires to the terminals.
>
> I always had the rig connected to the dummy load. I would key and
> try to check for voltages on the terminals( hoping to see the relay
> keying
> voltages). Apparently i did not see any. I tried to hit the PTT on the
> stock microphone.
>
> Now, when i power on, i see the "ON AIR" red LED on. If i key down, i
> get full output to the dummy load. But i don't hear any stations. But
> if
> i change modes or manipulate the keypad, i hear the beeps. I also don't
> see the 'S' meter move. I checked and double checked the usual murphy
> steps before shooting out this email. May be i fried the front end :(
>
> Before i started mucking with it, i was able to hear stations at about
> s2/3 via the dummy load on the MFJ-949E. :)
>
> Anyone got any tip for me .
> 1) I need to make an interface cable to hook up the amp. ??
> 2) Any clues as to what could have gone wrong with the TS-440( a stuck
> relay perhaps).??
>
> Looks like its time to drive down south to the Kenwood service center.
> :(
>
> I have been depressed all afternoon.
>
> Once again, Thank you all.
>
> 73's
> krish
> w4/vu2vku
>
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