Hi Everyone,
Just set up my station and started to receive all the main satellites, using a Gulf satellite antenna (2M + 70cm) + SSB 70cm Preamp and FT736R
When I transmit on 2M, especially FM, it's as if the preamp is squelching - the receive signal reduces significantly. If I turn the preamp off I don't get the problem, I can continue to hear the received signal.
Any ideas?
Peter Wilson G8KEK AMSAT UK 6897
Hi Peter,
Your preamp is overloading. See this article:
http://www.amsat.org/amsat-new/articles/Mode-J/http://www.amsat.org/amsat-new/articles/Mode-J/
73, Tony AA2TX
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At 01:51 PM 4/11/2010, Peter Wilson wrote:
Hi Everyone,
Just set up my station and started to receive all the main satellites, using a Gulf satellite antenna (2M + 70cm) + SSB 70cm Preamp and FT736R
When I transmit on 2M, especially FM, it's as if the preamp is squelching - the receive signal reduces significantly. If I turn the preamp off I don't get the problem, I can continue to hear the received signal.
Any ideas?
Peter Wilson G8KEK AMSAT UK 6897 _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Peter, Signal from your transmitter is de-sensing your preamp. It could be 2 Meter, white noise, or 3 harmonic. The third harmonic could come from the transmitter or it could be made by corrosion on the antenna connections. I suggest you check all elements and their connections including the antenna connectors first. Next step is to make or by filters or try a diplexer. If you make your own filters start with the RSGB VHF/UHF Manual I has great ideas and practical information for construction of all types of electronics including filters.
Art, KC6UQH
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Peter Wilson Sent: Sunday, April 11, 2010 10:51 AM To: Amsat BB Subject: [amsat-bb] SSB 70cm Pre AMp
Hi Everyone,
Just set up my station and started to receive all the main satellites, using a Gulf satellite antenna (2M + 70cm) + SSB 70cm Preamp and FT736R
When I transmit on 2M, especially FM, it's as if the preamp is squelching - the receive signal reduces significantly. If I turn the preamp off I don't get the problem, I can continue to hear the received signal.
Any ideas?
Peter Wilson G8KEK AMSAT UK 6897 _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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participants (3)
-
Anthony Monteiro -
Art McBride -
Peter Wilson