[R-390] Signal Amplifier Needed

[Scott, Barry (Clyde B)]

Roy,

Don't have a URM-25.  This is the General Radio GR1001A.  It currently has a
plug in the hi output connection.

(Shhhhhh!  Don't tell anyone how I get those great sensitivity
measurements...)

Barry(III) - N4BUQ

> -----Original Message-----
> From: Roy Morgan [mailto:roy.morgan@nist.gov]
> Sent: Monday, March 22, 2004 2:42 PM
> To: Scott, Barry (Clyde B)
> Cc: R390 (E-mail)
> Subject: RE: [R-390] Signal Amplifier Needed
> 
> 
> At 12:58 PM 3/22/2004 -0600, you wrote:
> >  ... use the "high-power" output on the signal to drive
> >the counter while using the attenuated output for the radio.
> 
> Barry,
> 
> The X200K one.. oh yes. You didn't say you had a URM-25 (I assume you 
> do.)  It appears to me from the schematic that both the X200K 
> output jack 
> and the attenuator have signal when the output switch is in 
> either of the 
> X200Kpositions (10 kc to 300 kc or 300 kc to 50 mc.)
> 
> Note, however, that the connection from the high level output to the 
> counter, and then inside the counter can/will leak a lot of 
> signal... so if 
> you are doing low level sensitivity measurements, do not use 
> the high level 
> output and cap it off.  With even moderate leakage, it's possible to 
> "measure" receiver sensitivities that are unbelievably low!  
> (Leaked signal 
> travels from the high level output and wire and counter to 
> the receiver 
> input and adds to the very low signal from the generator attenuator.
> 
> Roy
> 
> 
> 
> - Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
> 7130 Panorama Drive, Derwood MD 20855
> Home: 301-330-8828 Work: Voice: 301-975-3254,  Fax: 301-948-6213
> roy.morgan@nist.gov --
>