[R-390] Help getting unstuck!

[Craig C. Heaton]

Craig,

Let us know what it is when you fix it.

Tnx

Chuck


Chuck/All:

Tried the usual fixes: Checked C327 & C286, they were both fine according to
the TO-6A. Decided to read some of the older archives and found a post in
April of 2000 with a solution worth an attempt.

Seems another Motorola owner had the same low sensitivity symptoms below
8MHz and noticed an open connection on pin 7 of V207. He installed a jumper
between pins 2 & 7, to fix his dilemma. Looking at a pin-out of that tube it
has an internal connection between 2 and 7, I couldn't see where adding a
jumper on the tube socket would make a difference. My Motorola was the same
and had some flakey readings on pins 5 and 6 also.  What the heck, it would
only take a few minutes to try. Well it worked! Now have all bands working
fine. Could of been a bad solder joint on pins 2 or 7??

By the way, while going through the RF coil alignment per Y2K R1, I thought
the sensitivity of the lower bands were still below those above 8MHz. So I
went back to section 4 and ran the sensitivity test as per 4.3.1. 750kHz and
3.25MHz were lower than the rest. Peaking T207 on the RF deck brought those
two up to spec. So now, with a URM-25D with no sticker traceable to NIST,
the sensitivity is 3uV or just below.

Next step is to put up an antenna better than a test lead.

Tnx for all the help, those who wrote the Y2K manual and post information on
this reflector are a great asset!

73's
   Craig