[Test-Equipment] General Radio 1001-A Signal Generator

[Richard Knoppow]

-----Original Message-----
>From: ~DA~ <iluznst at yahoo.com>
>Sent: Apr 24, 2007 12:36 AM
>To: test-equipment at mailman.qth.net
>Subject: [Test-Equipment] General Radio 1001-A Signal Generator
>
>Hi,
>
>I have few questions about my new "black-box", as my
>wife and her friends like to call all my radio gear.
>
>This is the older style with the round
>carrier/modulation meter before they switched to the
>oval one, S/N 988.
>
>I would like to find an original 2 wire power cord as
>this one is missing and I don't really want to modify
>it to a 3; the unit is almost as good as the day it
>left the factory.
>
>Also any suggestions/recommendations on a where to get
>an original probe, I plan on using it mainly for
>alignment of old Hallicrafters, Nationals, BC-348s,
>etc.
>
>I have a GR 874 to BNC adapter, GR 874 to adapter and
>found a GR 874 to BNC via coaxial cable today at a
>local
>we-have-it-all-buried-somewhere-out-there-go-find-it-yourself
>electrical & machine store. They might have
>everything, but since I'm not an archaeologist my
>patience ran out after 3 hours of digging around.
>
>I know this piece of gear is way overkill for my
>purposes, but if you've ever seen one you understand,
>plus the price was right.
>
>Thanks,
>
>Doug
>
    For a long time a standard 2 wire female plug was made which fits the socket on GR equipment. The original cords are getting old enough now so that many have rotted. A search around old hardware stores may find the right connector.
    There are two instruction manuals on the BAMA site. One for the older version with the round meter and one for the later one with gray paint and oval meter. The later one has pictures of the chassis which helps to identify parts, the earlier one has a clearer schematic. 
     You need two attachments, which you can make. One is a 40 ohm series resistor and the other is a 50 ohm termination 
The output attenuator has an internal resistance of 10 ohms on all but the highest setting so the 40 ohm resistor is necessary to make it read right when feeding a 50 ohm load. On the highest range the output impedance is 50 ohms so the series unit can be removed. 
      I have an older version of the generator. I've discovered that it has hum induced by the power transformer. I used a sheet of magnetic shielding just under the transformer, which helps but does not completely get rid of the hum. 
      Some (maybe all) of these units have a two or three Black Beauty capacitors in them. They should be replaced by disc ceramics or some other kind of high quality, low leakage, capacitor. 
       Most GR stuff will last forever but I've found a surprising number of poor solder joints in them. Reheating the joints will fix a lot of odd problems. 

 


--
Richard Knoppow
dickburk at ix.netcom.com
Los Angeles, CA, USA