BCD436HP/BCD536HP: Need some advice - programming

First off, sorry if this is posted in the wrong area but I just recently purchased the BCD436HP and I'm trying to program a fairly new radio system but I'm confused as what needs programmed and if it gets programmed as a Motorola or P25 system?

I know it's a P25 compliant Motorola coded system, the paper I looked at had 4 frequencies in red - transmit, 4 - blue - Receive then it had a seperate area with the 2 rows of frequencies, colume one said (freq 1), colume 2 said (freq 2) and the 3rd colume had (sep) with 4 digit numbers listed, (example 0.400). In both columes of frequencies some were listed in red and some in blue.

Any advice would be appreciated and Thank You in advance.

For each SITE (the list on the left) there should be one red and up to 3 blue frequencies (reading across to the right). Add those (red and blue) to your scanner under a system of the "Motorola" type, and make sure you have Control Channel Only checked.

Only program it as P25 if it's listed as a P25 system type (not Motorola).

Red and blue have nothing to do with TX/RX. Red are primary control channels and blue ones are the alternates.

It would be a lot easier to help you if you cited the page you were viewing.

This is very interesting.

So I should go into my favorites list to the site info where there are 15 frequencies listed and delete all the ones not shown in red or blue in the RR database?

RT48 said:

This is very interesting.

So I should go into my favorites list to the site info where there are 15 frequencies listed and delete all the ones not shown in red or blue in the RR database?

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Not advisable. The RR DB is not always correct on which frequencies are control channels (usually by no fault of the submitter or RR, but because the system operator has altered the setup). If the CC "rotates" onto a frequency you don't have programmed, you will lose the ability to receive the system.

I'll try that, how do you check the control channel only if programming from the scanner itself?

Jay911 said:

Not advisable. The RR DB is not always correct on which frequencies are control channels (usually by no fault of the submitter or RR, but because the system operator has altered the setup). If the CC "rotates" onto a frequency you don't have programmed, you will lose the ability to receive the system.

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On the other hand, if you have all the other channels in, it increases the chance of losing the system you want because the scanner is hearing a system that uses one of the frequencies for control that is voice-only on the system you want, so it starts tracking the unwanted system.

While RR has it's share of issues, control channels are usually found pretty easily, and are correct on most systems.

Voyager said:

On the other hand, if you have all the other channels in, it increases the chance of losing the system you want because the scanner is hearing a system that uses one of the frequencies for control that is voice-only on the system you want, so it starts tracking the unwanted system.

While RR has it's share of issues, control channels are usually found pretty easily, and are correct on most systems.

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The FCC has done a pretty poor job of licensing if this happens. The odds are much better that a system admin has made a system change that RR has not caught up to than the FCC has allowed a conflicting channel on one system within range of a second system.

I generally add all the frequencies and have never in years of scanning had my scanner start tracking a different system because of such an event.

I suppose it is theoretically possible that the FCC has made such a mistake and that the first system owner has not brought it to their attention (because it would cause them problems too, not just the scanner world.)

Mark
536HP/HP1e/HP2e/996P2/996XT
996T/396XT(2)/PSR800/PRO668

marksmith said:

The FCC has done a pretty poor job of licensing if this happens. The odds are much better that a system admin has made a system change that RR has not caught up to than the FCC has allowed a conflicting channel on one system within range of a second system.

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While it's true that overlap shouldn't occur except in cases of significant congestion, in my experience, the government's response is essentially that the nature of trunking (control channels, NAC and connect tones) will prevent cross-system roaming. That or, "you're responsible for any interference you cause" (that's what it's like here).

A professionally programmed radio on a trunk system is going to 'know' which channels could be in the control channel rotation. Scanners have two compromises: One, data submitted to RR, or any other site, is not guaranteed to be perfectly accurate - even those where the system admin has shared the data himself/herself could get outdated eventually (including on purpose, to prevent "unauthorized" monitoring). Two, scanners don't link the programming you've put into them to the intended system. A pro radio programmed to talk to system ABCD on frequency 866.5375 is not going to listen to system CDEF on that same frequency. A scanner, however, if the signal is the same system type it's programmed for, will be happy to receive the system even if it's "not the right one".

If you are in an area where you can't guarantee that systems of the same type are separated frequency-wise or distance-wise, this might be a problem. If you are absolutely certain that all the control channels are identified in the RRDB, feel free to program only them. However, if you have any doubt that you have all the channels that could be CCs, it's wise to program them all in.

As for the question posed about how to enable control channel only mode, I am 99% certain that Uniden radios with up-to-date firmware (any model that allows firmware updates, from the 396T era up) has CC-only permanently enabled for Motorola 800/900 and all P25 systems.

I'm not sure what to make of this statement from page 5 of the manual:

"Control Channel Only Scanning – With Motorola trunking frequencies, you do not have to
program voice channel frequencies."

RT48 said:

I'm not sure what to make of this statement from page 5 of the manual:

"Control Channel Only Scanning – With Motorola trunking frequencies, you do not have to
program voice channel frequencies."

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If you're programming a Motorola or P25 trunked system, you only need the control channel frequencies - the data on the control channel tells the radio what frequency to tune to. Other trunking protocols like EDACS and LTR require all the known frequencies, and listed in correct order, in order to track conversations.

The problem is, the RR database doesn't always have all the correct control channel frequencies. If you only put in the red and blue frequencies from the RR DB, you run the risk of possibly losing reception if the system moves the control channel to a frequency that isn't listed as a control channel in the RR DB.

If you are 100% certain of which channels can be the control channels, and/or your CC never, ever changes frequencies (there are some such systems out there), program in only the CCs and enjoy.

marksmith said:

The FCC has done a pretty poor job of licensing if this happens. The odds are much better that a system admin has made a system change that RR has not caught up to than the FCC has allowed a conflicting channel on one system within range of a second system.

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I've had it happen with two systems that are about 75 miles apart. How much farther do you think the FCC should go? When you're between them, you might pick up either. One advantage is that the one system changed to P25 about a year ago, so that helped. But a few months ago the other changed to P25... problem back!

It doesn't cause the users problems since they only operate within their service areas.

Not that I'm defending an FCC that in the past has licensed two repeaters two city blocks away from each other...

Voyager, please check you PM.

I also follow Voyager's advice for the same reason here in Los Angeles. The area is so radio-dense that even if a voice channel (VC) of one TRS does not exactly coincide with a control (CC) of another, the adjacent interference from a strong signal nearby can interrupt the CC decoding on your target TRS. I always try to program only CCs and alternate CCs. The very worse that can happen (happened once to me a few years ago) is that if TRS administrator moves CC to a frequency you don't have programmed, it is relatively simple with today's scanners or an SDR dongle and Unitrunker to find the missing CC.
The benefit of CC/alternate CC programming for systems like Motorola outweighs the potential for a problem like Voyager described when you program all frequencies, at least in rio-dense areas like So. Calif.

Steve AA6IO

Radio-dense areas
Steve

squadman said:

First off, sorry if this is posted in the wrong area but I just recently purchased the BCD436HP and I'm trying to program a fairly new radio system but I'm confused as what needs programmed and if it gets programmed as a Motorola or P25 system?

I know it's a P25 compliant Motorola coded system, the paper I looked at had 4 frequencies in red - transmit, 4 - blue - Receive then it had a seperate area with the 2 rows of frequencies, colume one said (freq 1), colume 2 said (freq 2) and the 3rd colume had (sep) with 4 digit numbers listed, (example 0.400). In both columes of frequencies some were listed in red and some in blue.

Any advice would be appreciated and Thank You in advance.

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Attached is what I'm referring to

I think people here were mistaking what you were saying for the RadioReference database, which has frequencies colored in blue and red as well.

If it's a P25 system, it needs to be programmed as P25, regardless of who constructed it, be they Motorola, Harris, Raytheon, or Fisher-Price or anyone else.

It would help if we knew what that paper was from. The "Transmit" could be the frequency the tower transmits on, or it could be the frequency the subscriber radios transmit on. Either of those make a big difference. If it's the tower's transmit frequency, that's what you need to put in your scanner. If it's the radios' transmit frequency, you need to put the other set of frequencies (the receive set) in your scanner.

What I would do, if you can't determine the above, is program in two sites in Sentinel, one with the transmit frequencies as the site freqs and one with the receive frequencies. Whichever one works is the one that is the correct programming. Also make sure you select ID search, since you likely won't have any talkgroups programmed.

I would also recommend you submit the data to the RR database once you figure the system out, so others don't have to go through these steps

Jay911 said:

I think people here were mistaking what you were saying for the RadioReference database, which has frequencies colored in blue and red as well.

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I was...

Jay911 said:

... Harris, Raytheon, or Fisher-Price or anyone else.

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I think you meant Tyco. Or were they bought out again.

Jay911 said:

I think people here were mistaking what you were saying for the RadioReference database, which has frequencies colored in blue and red as well.

If it's a P25 system, it needs to be programmed as P25, regardless of who constructed it, be they Motorola, Harris, Raytheon, or Fisher-Price or anyone else.

It would help if we knew what that paper was from. The "Transmit" could be the frequency the tower transmits on, or it could be the frequency the subscriber radios transmit on. Either of those make a big difference. If it's the tower's transmit frequency, that's what you need to put in your scanner. If it's the radios' transmit frequency, you need to put the other set of frequencies (the receive set) in your scanner.

What I would do, if you can't determine the above, is program in two sites in Sentinel, one with the transmit frequencies as the site freqs and one with the receive frequencies. Whichever one works is the one that is the correct programming. Also make sure you select ID search, since you likely won't have any talkgroups programmed.

I would also recommend you submit the data to the RR database once you figure the system out, so others don't have to go through these steps

Click to expand...

Thanks for the info, I did get it programmed but 2 out of 4 channels are encrypted.