Somersworth --- tone out

[mainetrunk]

I've been hearing the strangest thing. On 157.375 ( a marine channel ) I've been hearing Somersworth dispatch on 157.375--nac-007, only on --all calls?-- fire, AMR and pd to situation.. Never a response, just the tone out. Is that wild / weird or what??

 

[ecps92]

It's called an image. Likely of one of the 151-156 frequencies that they are using for the All Call

I've been hearing the strangest thing. On 157.375 ( a marine channel ) I've been hearing Somersworth dispatch on 157.375--nac-007, only on --all calls?-- fire, AMR and pd to situation.. Never a response, just the tone out. Is that wild / weird or what??

 

[mainetrunk]

Wild, thx Bill--every public safety -fd-ems-pd entity 151--156 got 1 of those or is it a special request?

 

[ecps92]

Got one of what ??

What you are hearing is likely 151.0400 the input to the 155.8800 Repeater

Wild, thx Bill--every public safety -fd-ems-pd entity 151--156 got 1 of those or is it a special request?

 

[mainetrunk]

Does everyone 151--156 have an image or special request? I know their repeater freqs, I,m 5 miles away and watched that system grow from simplex analog to p25 repeater.. Just the dpw is still simplex analog. Fire was repeater since I've started scanning..

 

[ecps92]

Image Frequencies - The RadioReference Wiki

Does everyone 151--156 have an image or special request? I know their repeater freqs, I,m 5 miles away and watched that system grow from simplex analog to p25 repeater.. Just the dpw is still simplex analog. Fire was repeater since I've started scanning..

 

[mainetrunk]

Ahhh, yes I've heard those. More like a -phantom freq-.. Thx again Bill!

 

[jmarcel66]

Did you say you only get it when Fire/EMS "and" Police are being dispatched to a call?

 

[mainetrunk]

Yes sir!! ONLY when toned out, no responses what so ever.. I can hear the pd on 151.040--I know what it is, just saying..Other wise, 157.735, tone out ONLY...

 

[jmarcel66]

They may either be using a different site near you and/or if they simulcast on the Fire and Police frequencies during a dispatch it's mixing to create the image frequency.

Either way, it's not a real frequency in use; simply a phantom being created.

 

[mainetrunk]

Wild, I can still use it though to hear the tone out. I oughta run a marine channel scan to see what happens.

 

[ecps92]

I hope you understand they are not actually using that Frequency.

Your scanner is hearing / mixing frequencies and that make/model just happens to be hearing it on 157.xxxx

Wild, I can still use it though to hear the tone out. I oughta run a marine channel scan to see what happens.

 

[mainetrunk]

Oh yeah, but it works, . You can either listen to their fire channel, get who is responding to what, then they have the pd channel which AMR is dispatched on, a freq that they keep messing with. 1 minute AMR tone is analog, next p25, next tone is analog and dispatch is p25. This way I hear the all call only. ..Thx for the info guys.

 

[ecps92]

Yes, likely only on that Scanner Only

Oh yeah, but it works, . You can either listen to their fire channel, get who is responding to what, then they have the pd channel which AMR is dispatched on, a freq that they keep messing with. 1 minute AMR tone is analog, next p25, next tone is analog and dispatch is p25. This way I hear the all call only. ..Thx for the info guys.

 

[mainetrunk]

No---It's on all my scanners.. 1 weird signal. On a marine freq yet, weird.. Actually, Ive heard this before. I'll do a few dozen tests, see how many entities throw a phantom freq. Somersworth can't be the -only- 1..Hmmmmmm

 

[SCPD]

Intermodulation....

No---It's on all my scanners.. 1 weird signal. On a marine freq yet, weird.. Actually, Ive heard this before. I'll do a few dozen tests, see how many entities throw a phantom freq. Somersworth can't be the -only- 1..Hmmmmmm

The transmitter for both the police (155.880) and fire (154.385) are located together at the abandoned school atop the hill downtown. When they simulcast the difference between the two frequencies is 1.495 MHz. When you add 155.880 and 1.495 you get 157.375 MHz, the frequency you are hearing.

A classic case of intermodulation....nothing wrong with your receivers.

 

[mainetrunk]

Thank you sir, really? transmitter at top of mt. Vernon st. huh? I was wonderring where it was, thanks. Think the dpw will go repeater next?