Rock Island, IL, where I used to live, still has a channel 4 on VHF channel 4.
73s John AA5JG
----- Original Message ----- From: "Charles Suprin" hamaa1vs@gmail.com To: "Bob Bruninga" bruninga@usna.edu Cc: amsat-bb@amsat.org; "Gordon JC Pearce" gordonjcp@gjcp.net Sent: Wednesday, December 07, 2011 9:48 PM Subject: [amsat-bb] Re: 2 Meter TV Interference
I didn't think there were any vhf stations left. All the numbers on the channels now are virtual. All the tv antenna plans are for uhf bands. A quick look in the Boston market and the lowest channel is 19, channel 2@500MHz. Are there places that still use vhf?
Charles On Dec 7, 2011 1:38 PM, "Bob Bruninga" bruninga@usna.edu wrote:
HPF above 500 MHz? Then the TV would not be able to see anything but a few UHF channels.
What is needed is a stub filter. Just a piece of open ended coax 13" long "T"ed into the antenna lead....
The 13" is about 66% of a quarter wave at 2 meters.
Done
Bob, WB4APR
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Gordon JC Pearce Sent: Wednesday, December 07, 2011 3:02 AM To: amsat-bb@amsat.org Subject: [amsat-bb] Re: 2 Meter TV Interference
On Tue, 6 Dec 2011 21:17:55 -0600 Wyatt Dirks wyattdirks@msn.com wrote:
Just recently I have been having troubles with a neighbor while I am
working the FM satellites(SO-50 and AO-27). The setup I am currently using is my mobile setup because I am unable to put a base station up for many reasons. I am using a FT8900 with 50 watts out into a 1/4 wave or 1/2 Larson mobile antenna.The 1/4 wave is mounted permanently via a hole in the roof of my truck an the 1/2 wave is mounted on a mount opposite the factory installed FM/AM radio whip. It doesn't seem to matter what antenna I use for the problem to occur. Then I use either the arrow antenna or my cju for the downlink.
Use 5W into a hand-held Yagi. You'll get far better results.
Today I had another local ham over at the request of the neighbor and his
mobile Kenwood radio did the same thing to the neighbors tv when he transmitted on 2 meter with 50 watts out. He also recommended that they get a filter. I did not see the specs on the filter nor do I know what bandwidth it was for.
What you want is a highpass filter that will lop off everything below 500MHz. The chances are that your TX output is clean enough but the little amplifier in the splitter for the TV is causing all sorts of intermod - and probably covers from broadcast VHF radio to the top of the TV band.
-- Gordon JC Pearce MM0YEQ gordonjcp@gjcp.net _______________________________________________ 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
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
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