[1000mp] MkV blown front end fixed

Sun, 7 Sep 2003 08:06:32 +0200

Hello Lou,

Congratulations! Very good to read that you have fixed it by replacing both
the transistors.

Yes, this is a very tricky job. The same occured when you want to replace
the fuse for the external +13,5 Volt source. In the 1000MP this was a very
easy job.

I will print your message and keep it together with my manual and several
other mods.

Thanks for keeping us informed!

Enjoy your Mark V again and nice weekeind.

73, Hans Remeeus.
Ham Radio: PA1HR
www.remeeus.nl

Communication is about people, the rest is technology.

----- Original Message -----
From: "lhlousek" <[email protected]>
To: "1000mp list" <[email protected]>
Sent: Sunday, September 07, 2003 4:16 AM
Subject: [1000mp] MkV blown front end fixed

I got back into town last night after a week away from home on business and
continued digging into my MkV to troubleshoot the lack of RX.   As said last
week,  there is a T/R circuit at the antenna input to the rig that employs
three transistors, a pin diode switch, and a relay. The relay wasn't being
activated. I was able to make the relay work by supplying 12V to it and the
rig received fine. Today I did some troubleshooting and found that Q6451 was
bad. I replaced it, and while I was at it, I also replaced Q6450. I verified
correct operation of the circuit and the rig works FB now.

Troubleshooting the problem and replacing the transistors was relatively
straight forward.  Digging into the rig and getting the main antenna tuner
board out was pretty tricky.  If you have any questions, don't hesitate to
ask.

Lou W7HV