Local Interference
 

Hi All:

I have a radio shack DX394 and an RF Systems EMF antenna. From about 7020
through 7180 or so I am getting interference from KYCH 97.1 FM. I can
recognize the song playing.

Is something likely wrong with my radio, antenna or is it them? Or could
it be that I am pretty close to their transmitter?

This is in Portland Oregon

Kevin

Local Interference
 

On 27 Aug 2006 19:58:01 GMT, Kevin Garrett wrote:

KYCH
Are you near he

http://tinyurl.com/p2mtt

Local Interference
 

David wrote in news:5a24f258muct3godvbu426anv7qd5ap985@
4ax.com:

On 27 Aug 2006 19:58:01 GMT, Kevin Garrett wrote:

KYCH
Are you near he

http://tinyurl.com/p2mtt


about 4 or 5 miles west of that

Local Interference
 

Kevin Garrett wrote:
Hi All:

I have a radio shack DX394 and an RF Systems EMF antenna. From about 7020
through 7180 or so I am getting interference from KYCH 97.1 FM. I can
recognize the song playing.

Is something likely wrong with my radio, antenna or is it them? Or could
it be that I am pretty close to their transmitter?

This is in Portland Oregon

Kevin

An FM BCB rejection trap might solve your problems.

Several compaines make them.

Radio Shack (shudder) makes an inline "F" to "F" unit that works pretty
well.

I have a PCR1000 that suffers from local FM BCB overlaod. And a local
rat
shack was having a going out of business sale. So I bought the last
four
they had for about $1 each. One was enough to completly remove the
FM interference.

At full price they shouldn't break the bank.

Terry

Local Interference
 

Kevin Garrett wrote:
Hi All:

I have a radio shack DX394 and an RF Systems EMF antenna. From about 7020
through 7180 or so I am getting interference from KYCH 97.1 FM. I can
recognize the song playing.

Is something likely wrong with my radio, antenna or is it them? Or could
it be that I am pretty close to their transmitter?

This is in Portland Oregon

Kevin

Kevin, this is VHF image interference related to the 1st IF of 45 MHz.
The 1st local oscillator is at 52.1 MHz to tune in 7.1 MHz- -
difference equals 45 MHz, but 97.1 MHz also produces a diff of 45 MHz.
While the DX-394 does have a filter in the Lo-Z input to suppress
signals above 30 MHz, its stop-band attenuation is not enough to
prevent strong VHF signals from breaking through. Add an ouboard 30-40
MHz lowpass filter in the coax line between the antenna and LO-Z input
to increase the VHF attenuation.

Also, for more info on the DX-394, join the user group at
http://groups.yahoo.com/group/RADIOSHACKDX394/ .

Tom

Local Interference
 

"Tom" wrote in
oups.com:


Kevin Garrett wrote:
Hi All:

I have a radio shack DX394 and an RF Systems EMF antenna. From about
7020 through 7180 or so I am getting interference from KYCH 97.1 FM.
I can recognize the song playing.

Is something likely wrong with my radio, antenna or is it them? Or
could it be that I am pretty close to their transmitter?

This is in Portland Oregon

Kevin

Kevin, this is VHF image interference related to the 1st IF of 45 MHz.
The 1st local oscillator is at 52.1 MHz to tune in 7.1 MHz- -
difference equals 45 MHz, but 97.1 MHz also produces a diff of 45 MHz.
While the DX-394 does have a filter in the Lo-Z input to suppress
signals above 30 MHz, its stop-band attenuation is not enough to
prevent strong VHF signals from breaking through. Add an ouboard 30-40
MHz lowpass filter in the coax line between the antenna and LO-Z input
to increase the VHF attenuation.

Also, for more info on the DX-394, join the user group at
http://groups.yahoo.com/group/RADIOSHACKDX394/ .

Tom


Thanks Tom

Would that be something like this? http://www.grove-ent.com/FTR-FM.html

Local Interference
 

Kevin Garrett wrote:
"Tom" wrote in
Kevin, this is VHF image interference related to the 1st IF of 45 MHz.
The 1st local oscillator is at 52.1 MHz to tune in 7.1 MHz- -
difference equals 45 MHz, but 97.1 MHz also produces a diff of 45 MHz.
While the DX-394 does have a filter in the Lo-Z input to suppress
signals above 30 MHz, its stop-band attenuation is not enough to
prevent strong VHF signals from breaking through. Add an ouboard 30-40
MHz lowpass filter in the coax line between the antenna and LO-Z input
to increase the VHF attenuation.

Also, for more info on the DX-394, join the user group at
http://groups.yahoo.com/group/RADIOSHACKDX394/ .

Tom


Thanks Tom

Would that be something like this? http://www.grove-ent.com/FTR-FM.html

That would work to attenuate the VHF-FM band only but is probably
rather pricey and will kthelp if you have images from VHF aeronautical
band et al from 108-120 MHz. Look on ebay for ham/CB TVI low pass
filters designed to pass everything below 30 MHz and to attenuate
above. Here's a search URL:
http://search.ebay.com/search/search...6c atref%3DC6

Good luck,

Tom