On Sun, 26 Jan 2014 10:25:16 -0500, "Ralph Mowery"
wrote:

"Jeff Liebermann" wrote in message
.. .

At the time, I used a Gertsch FM-something. It's the box with only
the left handle showing at the extreme right of the pictu
http://802.11junk.com/jeffl/pics/Old%20Repeaters/slides/PMC02.html

I can not tell what the Gertsch is from the pix. I have a Singer/Gertsch
FM-10C, but it looks to be older than that.

I tried to find a better photo of the generator, but couldn't. It's a
Gertsch FM-7 and DM-3 modulation meter combination, which is partly
shown in the photo. I think it looked something like this:
http://www.ebay.com/itm/141159577401
The Measurements (later Boonton) Model 80 was my "calibrated" signal
source. I let it drift onto frequency using the FM-7, and used it to
measure sensitivity. If left on continuously, it was stable enough
for the old 50 KHz wide band radios.

Do see the old generator next to
the scope. I have one like that and play with it from time to time.

http://www.ko4bb.com/Manuals/09)_Misc_Test_Equipment/Boonton/Boonton_Model_80_Manual.pdf
I still have some acorn tubes for it buried somewhere.

Checked the output amplitude of it with my hp 8924c and it seems to be very
close allowing for the fact it is an analog dial and you have to set it to
the mark on the meter.

I had ours calibrated along with the FM-7. In order to operate in the
UHF commercial band (about 463 MHz), we had to use the 3rd harmonic
through a multiplier. It also lacked FM modulation which I added with
a varactor (varicap) diode. The techs said it was quite accurate and
fairly stable in the UHF region. I also had another RF source
consisting of the exciter chain from an old radio. Not the best, but
since it was crystal controlled, it was at least stable. For the late
1960's and early 1970's, it wasn't a bad arrangement.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558