BCD325P2/BCD996P2: BCD325P2 Programming 5 decimal (50 KHz) control channels

[lgcooper]

I'm trying to program a BCD325P2 for our local P25 Phase II trunked system (Monroe/Ontario County, NY) using Proscan (v 22.5), BCD firmware 1.08.01)
The control channel frequencies listed use 5 decimal places, i.e.: 769.08125 however when imported into Proscan, or even trying to manually enter it in the radio once saved it omits the last digit and shortens it to 769.0812. How can this still work? Is there a step increment or something I need to change to accept the 5th digit? Site info: Monroe/Ontario Counties Trunking System, Regional, New York

I'm not receiving anything on the trunked talk groups, and wondering if this is because the control channel frequencies aren't exact (being rounded to 4 digits) or whether it's just Simulcast distortion from the multiple transmitter locations at each site. But even when I select only one site near me (with 4 transmitting locations - one being within a 1/2 mile) and using a tiny stub antenna to reduce signal strength to minimize multi-site interference I still don't receive anything on any of the talk groups.

I assumed Simulcast would produce garbled and missed communications but thought I should as least hear something occastionally. Hence my question about if the control channel frequencies are actually being received when they omit the 5th digit past the decimal point.

 

[doctordialtone]

The 5th digit doesn't matter.

Read here

 

[jtwalker]

I assumed Simulcast would produce garbled and missed communications but thought I should as least hear something occasionally.

This is a bad assumption. It may produce garbled audio, or it may not even show that it is receiving by stopping on a TG, or it may receive fine based on your location.

 

[wtp]

my county is on a 700Mhz simulcast system.
i get to hear 1/4 second of audio, and then nothing for 1/4 second.
it works OK all around my county.
so the wife said OK to the SDS100...it works great. nothing missed.
i think, as a ham, you can drive around with the radio, try that.
if you hear stuff, it is simulcast problems.

 

[nessnet]

I'm trying to program a BCD325P2 for our local P25 Phase II trunked system (Monroe/Ontario County, NY) using Proscan (v 22.5), BCD firmware 1.08.01)
The control channel frequencies listed use 5 decimal places, i.e.: 769.08125 however when imported into Proscan, or even trying to manually enter it in the radio once saved it omits the last digit and shortens it to 769.0812. How can this still work? Is there a step increment or something I need to change to accept the 5th digit? Site info: Monroe/Ontario Counties Trunking System, Regional, New York

I'm not receiving anything on the trunked talk groups, and wondering if this is because the control channel frequencies aren't exact (being rounded to 4 digits) or whether it's just Simulcast distortion from the multiple transmitter locations at each site. But even when I select only one site near me (with 4 transmitting locations - one being within a 1/2 mile) and using a tiny stub antenna to reduce signal strength to minimize multi-site interference I still don't receive anything on any of the talk groups.

I assumed Simulcast would produce garbled and missed communications but thought I should as least hear something occastionally. Hence my question about if the control channel frequencies are actually being received when they omit the 5th digit past the decimal point.

For a bit now, (>+year) the 'rounding' done by either Sentinel and/or ProScan has bugged me.

I have, in the past brought it up to Bob.

Here, I have gotten the same response ("doesn't matter") - and yes, it doesn't, considering the rather 'wide' nature of the chip used in the 100/200.

But.... I have always wondered where the rounding occurred (?) The radios(s) themselves retain that 5th digit.
Read/write to Sentinel has always been whom I suspected to be the culprit. But, with ProScan I (think) I've seen it also.
Yes, it is technically not relevant. But as an engineer/PMI and (admittedly A/C), I've always 'wondered'.........

 

[wtp]

50 Hz not 50k
if you click on the doc's post it is mentioned there.

 

[ProScan]

For a bit now, (>+year) the 'rounding' done by either Sentinel and/or ProScan has bugged me.

I have, in the past brought it up to Bob.

Here, I have gotten the same response ("doesn't matter") - and yes, it doesn't, considering the rather 'wide' nature of the chip used in the 100/200.

But.... I have always wondered where the rounding occurred (?) The radios(s) themselves retain that 5th digit.
Read/write to Sentinel has always been whom I suspected to be the culprit. But, with ProScan I (think) I've seen it also.
Yes, it is technically not relevant. But as an engineer/PMI and (admittedly A/C), I've always 'wondered'.........

It's the scanner doing it. ProScan doesn't round or drop the last digit. If a channel with a frequency of 123.456789 was written to the scanner then the same frequency will show in ProScan after reading back. But when the scanner housekeeping function kicks in then the frequency will change to 123.456250.

{edit}
Inputting 123.45679 in the ProScan frequency box (which puts the scanner in Quick Search mode), shows 123.45833
In the Waterfall feature, inputting 123.45679 (at the scanner keypad) made the center frequency go to 123.4562

 

[donc13]

I'm trying to program a BCD325P2 for our local P25 Phase II trunked system (Monroe/Ontario County, NY) using Proscan (v 22.5), BCD firmware 1.08.01)
The control channel frequencies listed use 5 decimal places, i.e.: 769.08125 however when imported into Proscan, or even trying to manually enter it in the radio once saved it omits the last digit and shortens it to 769.0812. How can this still work? Is there a step increment or something I need to change to accept the 5th digit? Site info: Monroe/Ontario Counties Trunking System, Regional, New York

I'm not receiving anything on the trunked talk groups, and wondering if this is because the control channel frequencies aren't exact (being rounded to 4 digits) or whether it's just Simulcast distortion from the multiple transmitter locations at each site. But even when I select only one site near me (with 4 transmitting locations - one being within a 1/2 mile) and using a tiny stub antenna to reduce signal strength to minimize multi-site interference I still don't receive anything on any of the talk groups.

I assumed Simulcast would produce garbled and missed communications but thought I should as least hear something occastionally. Hence my question about if the control channel frequencies are actually being received when they omit the 5th digit past the decimal point.

No matter what site (tower) you select, if there are other towers (sites) broadcasting on the same frequency, you can get Simulcast distortion.

 

[lgcooper]

It's the scanner doing it. ProScan doesn't round or drop the last digit. If a channel with a frequency of 123.456789 was written to the scanner then the same frequency will show in ProScan after reading back. But when the scanner housekeeping function kicks in then the frequency will change to 123.456250.

{edit}
Inputting 123.45679 in the ProScan frequency box (which puts the scanner in Quick Search mode), shows 123.45833
In the Waterfall feature, inputting 123.45679 (at the scanner keypad) made the center frequency go to 123.4562

Hmm... Well, with the scanner type selected to BCD325P2, when I enter a control frequency of 769.08135 in Proscan (v22.5) it immediately changes it to 769.0814. When I manually enter the same frequency directly in the scanner it immediately changes it to 769.0813. So I assume the scanner only accepts 4 digits past the decimal which is why Proscan rounded it up (whereas the the radio instead truncates it a 4 digits).

Anyway, I guess the question then became whether the BCD325P2 can operate properly with control channels using 5 digits past the decimal.
From the answers provided above I'm told it doesn't matter and should work okay, so I guess my issues are all related to Simulcast.

 

[lgcooper]

50 Hz not 50k
if you click on the doc's post it is mentioned there.

Heh, heh... Yup! Senior moment there I caught that later but it was too late to change it!

 

[wtp]

and i say i am the one with a hole in my head (read my bio)

 

[JoeBearcat]

For a bit now, (>+year) the 'rounding' done by either Sentinel and/or ProScan has bugged me.

It's not rounding - it's masking. That means the frequency is correct even though the 5th digit is not shown.

You may see 453.0162 but the scanner 'sees' 453.01625.

BTW, if it really bugs you don't listen to the aircraft band where they say "Switch to 123.07" when they are talking about 123.075 MHz.

 

[wtp]

or 2307