BCD325P2/BCD996P2: Shortening antenna to Attenuate for Simulcast

[Golay]

A question about antenna length. I picked up a 325P2 at a charity auction. Wasn't really going to get back into scanning since my ol' RS Pro 96 scanner died several years ago, But couldn't pass it up once I looked on my phone and seen what they go for.

Everything I'm interested in is on a 4 tower simulcast system. It's my understanding the problem about receiving simulcast on scanners like mine is that the radio is receiving more than one tower. I live less than a mile from one of the towers, and at least 6 miles from each of the other three. My thought was to solder a piece of copper wire to a BNC connector (actually several for trial and error). And then start nipping the end off to where (theoretically) I'm only receiving the tower closest to me. Like I said, all I care about listening to is on this one system.

Anyone think doing this would reduce simulcast problems? Or are there other factors at play besides receiving multiple towers at the same time? Thanks. Link to my system below if anyone is interested:

Downriver Mutual Aid (Project 25) Radio System Trunking System, SE Wayne County, Michigan

Downriver Mutual Aid (Project 25) Radio System Trunking System Profile

www.radioreference.com

 

[hazrat8990]

Pretty sure it will work just like you're hoping. With your proximity to the site, you can probably get by with a thumbtack.

 

[wtp]

for a more professional look you could try to look up "race antenna"
i have one that is one and a half inches, but can't find it now.
and short antenna will work even if VHF or UHF.

and this one is actually longer.
but it is all i can find now. i guess they stopped making the other one.
you could also turn on attenuation on the scanner and lay it down to make it a bit directional.

 

[nessnet]

I didn't do the exact math, but let's say 852.00Mhz is the average.
A 1/4 wave antenna is 3.46 inches - 3.5 is close enough.
Do your BNC/copper wire with that length.

 

[ofd8001]

You might want to Google "Paper Clip Antenna", (seriously). Less is more with simulcast.

 

[hazrat8990]

I didn't do the exact math, but let's say 852.00Mhz is the average.
A 1/4 wave antenna is 3.46 inches.
Do your BNC/copper wire with that length.

His goal is to attenuate the signal, not improve it.

 

[brcoz]

About 20 years ago I picked up a rat shack racing antenna about 3/4 of an inch. There was a BNC to coax adapter that might work.

 

[nessnet]

His goal is to attenuate the signal, not improve it.

A 1/4 wave is just a good place to start.

 

[hazrat8990]

A 1/4 wave is just a good place to start.

True, but a severe mismatch will offer the attenuation needed. Something like a WiFi antenna may do the trick.

 

[Golay]

Thanks for the replies.
I decided to just take a pair of dykes to a 6" UHF antenna I had. Cut it down to about 3" or so. Reception has really picked up and still getting full scale bars. Based upon wtp's race antenna suggestion, I'm going to go ahead and buy one of those and see how it plays.

 

[JoeBearcat]

If you really want a short range antenna look for an Ethernet termination with a BNC connector.

 

[Golay]

If you really want a short range antenna look for an Ethernet termination with a BNC connector.

Actually one of the first things I tried before starting this thread. Radio was deaf. No bars at all.

Interesting thing also. I stood across the street from the site for awhile with no antenna. Also deaf which surprised me a bit.

 

[wtp]

Ethernet termination with a BNC connector

 

[Ubbe]

Scanner has an attenuate setting that will mimic a bad paperclip type of antenna.

/Ubbe

 

[JoeBearcat]

Interesting thing also. I stood across the street from the site for awhile with no antenna. Also deaf which surprised me a bit.

surpr5ises me, too. Maybe that site has other frequencies or is not active?

 

[dlwtrunked]

A question about antenna length. I picked up a 325P2 at a charity auction. Wasn't really going to get back into scanning since my ol' RS Pro 96 scanner died several years ago, But couldn't pass it up once I looked on my phone and seen what they go for.

Everything I'm interested in is on a 4 tower simulcast system. It's my understanding the problem about receiving simulcast on scanners like mine is that the radio is receiving more than one tower. I live less than a mile from one of the towers, and at least 6 miles from each of the other three. My thought was to solder a piece of copper wire to a BNC connector (actually several for trial and error). And then start nipping the end off to where (theoretically) I'm only receiving the tower closest to me. Like I said, all I care about listening to is on this one system.

Anyone think doing this would reduce simulcast problems? Or are there other factors at play besides receiving multiple towers at the same time? Thanks. Link to my system below if anyone is interested:

Downriver Mutual Aid (Project 25) Radio System Trunking System, SE Wayne County, Michigan

Downriver Mutual Aid (Project 25) Radio System Trunking System Profile

www.radioreference.com

Blocking the direction of the other towers at your receive antenna may be a better idea.