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Quantar Howl
Posted: Mon Apr 07, 2014 9:06 pm
by KG4LHQ
Having some issue with the Quantar howl at the end of some transmissions. If you have not heard this sound then please Youtube "Motorola Quantar Howling" and you can hear it very clear and this is exactly what mine sounds like at times randomly. Any fix?!?
Re: Quantar Howl
Posted: Tue Apr 08, 2014 5:50 am
by Bill_G
A little help
http://www.youtube.com/watch?v=SRfvh0UTFHw
I've worked a problem like the video before. It's simulcast howl caused by local desense in the antenna. In our case, the antenna was too close to other structures. Busy site, and all antennas were in the same horizontal plane. Stupidest mess I had ever seen. So, if you have THAT howl, you probably have a bad antenna or duplexer someplace.
Re: Quantar Howl
Posted: Mon Apr 14, 2014 12:36 pm
by motorola_otaku
Using braided coax on the full-duplex side (i.e. anywhere between the duplexer output and antenna) will also cause that. BTFDT.
Re: Quantar Howl
Posted: Mon Apr 14, 2014 8:02 pm
by d119
motorola_otaku wrote:BTFDT.
huh?
Re: Quantar Howl
Posted: Mon Apr 14, 2014 8:13 pm
by motorola_otaku
d119 wrote:motorola_otaku wrote:BTFDT.
huh?
been there effing done that
IMD and desense from braided coax on a repeater feed line is a sore subject for me.
Re: Quantar Howl
Posted: Tue Apr 15, 2014 7:20 am
by Bill_G
I agree. It can be anything in the transmission chain from the duplexer input to the antenna.
Re: Quantar Howl
Posted: Tue Apr 15, 2014 8:48 am
by escomm
Window filters are your friend