At 8/22/2004 11:57 PM, you wrote:
>I was wondering if there is any chance anyone has access to the users
>manual for the 2955 service monitor? I am having a hard time locating
>the gpib programming
>information for the unit and understand it is in the users manual. I do
>a lot of work for the local ham club setting up all the local repeaters.
>One of the projects I have going at the moment is to write aprogram for
>the 2955 gpib interface to automatically determine the repeater rx/tx
>audio frequency response using the 2955's duplex mode. I need to be able
>to send say 50 audio tones at about 5 audio levels and readback the
>performance from the 2955. A quick plot would show where de/pre-emphasis
>tracking falls apart, the pl lp filter action and the transmitter
>compression level as the deviation approaches the transmitters limit.
>I hope you can help.
Can't help with the 2955 manual, but wanted to say that I'm working on
doing the same kind of measurements with an ordinary pair of transceivers &
computer sound card. For repeater frequency response, I generate a swept
tone with the sound card which gets fed into the modulator of the TX
radio. The discriminator of the RX radio is fed back into the sound card's
line input (a full-duplex sound card is required for this), & a spectrum
analyzer program with peak hold feature on the PC displays the frequency
response. At first I put the TX & RX on the same frequency to calibrate
the setup, then move them to the input & output of the repeater to be
tested. This method allows for remote testing of the repeater's frequency
response.
Bob NO6B
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/Repeater-Builder/
<*> To unsubscribe from this group, send an email to:
[EMAIL PROTECTED]
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
