Found CBP on 469.5625 !

[cjrjr507]

Hi CBP listeners
I was searching between 469.2000 & 470.0000 and heard the CBP on 469.5625. Did some checking on the net and it's just a business freq. so why would the CBP be using that freq., Hmmm. I can only figure that their repeater is transmitting on that freq too, strange. Unless that repeater is bleeding over onto that freq. Heard the dispatch & the agent in field; said he was on foot. I'm in northwest, mt., Libby. I checked my scanner and I'm pretty sure it's not an image freq. Whatever.

cjrjr507

 

[naSTI]

Were you able to confirm this transmission was happening simultaneously as the known VHF freq? Was it a strong or weak signal?

It is possible, as you somewhat alluded to that it maybe a multi-site repeater link freq. Unless it is a service to other local law enforcement to pick up their transmissions from their UHF service radios.

 

[ecps92]

If they were going to Link for Local/County/State to listen, they would

a.) Do it on the Regular Channels [Like VT]
b.) Link to a Public Safety Channel, Not a Business Allocation

Your either hearing the Image of the VHF Frequency or Intermod.

But, alas we don't know where you are and we are assuming the USA, but your profile
shows no location. Please update it.

Were you able to confirm this transmission was happening simultaneously as the known VHF freq? Was it a strong or weak signal?

It is possible, as you somewhat alluded to that it maybe a multi-site repeater link freq. Unless it is a service to other local law enforcement to pick up their transmissions from their UHF service radios.

 

[cjrjr507]

CBP on 469.5625

Were you able to confirm this transmission was happening simultaneously as the known VHF freq? Was it a strong or weak signal?

It is possible, as you somewhat alluded to that it maybe a multi-site repeater link freq. Unless it is a service to other local law enforcement to pick up their transmissions from their UHF service radios.

Hi naSTI
Did some checking and when the CBP transmit on 170.7750 I checked 469.5625 and the same transmission was on that freq. so I can only assume they are using that freq. for a simulcast on UHF as you refered to. You would think they would be between 406 - 420 MHZ govt. band. The signal is just somewhat weaker but not much and very clear. They could be on the govt. band but I have not found it yet or maybe I can't pick it up here. (I live in Libby, MT.) And I did the math for image frequencies for my radio and did not add up. I'll have to check the govt. band again and scan around it.

cjrjr507

 

[jawhite2]

CBP on 469.5625

Hello naSTI,

Can you tell where what you are hearing is coming from? MT or ID?
FYI I did a search for 469.5625 on the FCC website in MT and ID and found nothing.

Regards,

John

 

[SkipSanders]

I would have to call this as either an intermod/false response in the receiver (most likely), or a local actually monitoring and (illegally) retransmitting the signal for some reason (very unlikely).

If the feds were retransmitting, they'd do it on a fed channel.

 

[cjrjr507]

468.5625

Hello naSTI,

Can you tell where what you are hearing is coming from? MT or ID?
FYI I did a search for 469.5625 on the FCC website in MT and ID and found nothing.

Regards,

John

Hi jawhite2
The signal either comes from Bonner county, ID or Lincoln or Flathead county, MT. But I'm pretty sure it's out of Idaho. You won't find CBP frequencies on the FCC site, I've tried.
It's not an image frequency or intermod as far as I can tell. Maybe some badguy or whoever is retransmitting it.

Best regards,

Cecil (cjrjr507)

 

[cjrjr507]

CBP on 469.5625 ?

I would have to call this as either an intermod/false response in the receiver (most likely), or a local actually monitoring and (illegally) retransmitting the signal for some reason (very unlikely).

If the feds were retransmitting, they'd do it on a fed channel.

Hi SkipSanders

It can't be intermod as the intermod frequencies would have to be very close to the actual frequency; on either side of it as I did some checking about intermod on the net. And it can't be an image freq as my scanner uses an 10.8 IF and the formula is freq + 2*(10.8) for my radio which comes out to 192.3750 mhz

Regards,

cjrjr507

 

[torontokris]

Its listed as being for nationawide for bussiness, amusement parks etc
its even listed as a Nascar driver frequency
#79 Joe Aramendia 469.5625

Must be a bleed in.. I doubt they would be using such a common freq

 

[SkipSanders]

Hi SkipSanders

It can't be intermod as the intermod frequencies would have to be very close to the actual frequency; on either side of it as I did some checking about intermod on the net. And it can't be an image freq as my scanner uses an 10.8 IF and the formula is freq + 2*(10.8) for my radio which comes out to 192.3750 mhz

Regards,

cjrjr507

You show here a total lack of understanding of just how complex the subject of false responses/images in a modern all band synthesized scanner is.

No, a false response doesn't have to be 'close'. 870 MHZ cell phones often showed up on 350 MHz frequencies. There are a great many 'IF' frequencies in a modern scanner, not all of them on 'fixed' frequencies, and when you toss in harmonics, etc, things show up EVERYwhere.

It's even possible the customs repeater is putting out a spurious frequency itself. It can happen.

 

[ChrisP]

Hi, Cecil...

I'd have to second SkipSanders response and say that it's much more likely that you are hearing an image, a spur or some sort of mixing effect that CBP is really using 469.5625 MHz for some sort of relay.

Logically speaking, it would make no sense. The NTIA and the FCC would most likely never approve of such a setup. (Yes, despite what some people think, federal agencies have to get licensed from the NTIA. They don't just pick channels out of the air.) If the CBP needed some sort of relay or link, there are literally thousands of VHF, UHF or microwave frequencies that are allocated to federal agencies for them to use. Why would they intentionally pick a frequency in the middle of the mobile side of the UHF business band?

I can speak from personal experience that not all of what you hear on the scanner is exactly what is really going on. I have some local 2 meter ham repeaters that routinely show up ins some odd places in the federal bands. It seems to be due to some mixing of the VHF frequencies with other active channels at the time.

That is one of the frustrating things about RF - it sometimes behaves in ways that makes no sense...

- Chris

 

[Firetxmi]

Just a thought based on several experiences from my days near the northern border..... Could it be they are retransmitting to an assisting agency in Canada? I have seen similar things done before.

Just a thought. Maybe check the Industry Canada freq. search site.

Let me know what you think/find.

 

[commstar]

I was having the same thought as firetxmi with the following addition. Perhaps the CBP has nothing to do with this.

It takes little knowledge/money/expertise to crossband repeat this traffic. An example would be to use a scanner into a radio shack simplex repeater transmitting out on a uhf radio even a portable.

Why would some one want to do this? There could be a myriad of reasons that would not occur to us the casual observer. The fact that it is not licensed is interesting but not surprising especially if it is less than 500mw at least to me.

Then there is the outlaw factor, we are talking about an international border and its attendant hi-jinx.

On the other hand, in the Industry Canada search site, there is a licensee, Black Watch Security based in Vernon, BC. Do they have a contract presence on the Canadian side of the border?

" Black Watch Security Guard and Patrol Service
Serving the Okanagan since 1992. Professional & Reliable. Commercial and Residential. 24 hour company owned personal dispatch services. Seven days per week. Mobile Patrols & Stationary (Onsite)Security for: Special events, hospital, hotel, loss prevention, construction sites, resorts, floods, fire, alarm response, etc.
Telephone 1 250 558-0119 "

Extrapolating somewhat, Black Watch could have a contract adjacent to the port of entry and want to be able to listen to CBP 'port 2' while carrying a single radio. The CDA airport crossrepeats aircraft traffic onto 453.5000 (i think) for the airports maintainance staff so they only carry one radio.This is one-way they do not have the ability to transmit back into the airband.

Just some thoughts on the matter.