BCD436HP/BCD536HP: Bcd-436hp question

[Baker845]

I was looking into getting a 436hp scanner and was wondering if the scanner would be good choice for newer P25 trunk systems? I been reading that the scanner has issues with C4FM and LSM mixed systems? little confused on this.

 

[GTR8000]

If the site you're going to be monitoring is simulcast, you're probably going to have some issues. That's a general statement, as you could get lucky and be in a good location where simulcast distortion and multi-path is not a factor. Seeing as how the 436 is a handheld scanner, it's reasonable to assume that you'd be listening in more than one fixed location.

C4FM is normally the modulation used for non-simulcast P25 sites. LSM (Linear Simulcast Modulation) is Motorola's proprietary flavor of QPSK, which is almost always used on their P25 simulcast cells. TDMA voice channels, however, will use H-DQPSK modulation, which the 436 can also have some issues with.

Bottom line is that the SDS series are the only scanners to properly handle P25 trunked simulcast. There are other devices out there such as the Unication G series that will also work well.

 

[iMONITOR]

It all depends. I use a BC436HP & BCD536HP in Macomb County, Macomb Twp, MI on a 14 site P25 Phase 1 simulcast system and they both work perfectly! I have friends in Washington Twp, MI, and Richmond, MI that also use non-SDS scanners on the same system and they work perfectly. I also have a friend in Oregon that has used both the BC436HP & BCD536HP successfully.

Try posting the question in the Oregon forum and see if there anyone in your immediate area and ask what is working for them. No sense to spend more than you need to if they will work in your area. I should mention mobile while in motion may not work as well as base or stationary.

The SDS series are SDR (software defined radios) that have their own problems.

 

[Baker845]

well do, thank you all .

 

[fireman_dude]

I have the BCD436HP and have not had any issues with P25 simulcast sites but I only monitor 1 site (the closest in proximity to me). If you monitor multiple sites, that is where the 436HP runs in to the issue. You get what is known as simulcast distortion. The scanner will stop on a channel and you will hear no audio.

 

[ProScan]

I have the BCD436HP and have not had any issues with P25 simulcast sites but I only monitor 1 site (the closest in proximity to me). If you monitor multiple sites, that is where the 436HP runs in to the issue. You get what is known as simulcast distortion. The scanner will stop on a channel and you will hear no audio.

One little correction. Simulcast distortion is possible when monitoring just one site. That is if another site is transmitting the same frequencies at the same time. The frequencies at the site you are monitoring may not be simulcasted.

 

[RandyKuff]

Also, you cant select one specific site/tower locacation in a simulcast system...
All the Control Channels and Frequencys used pertain to all the sites (However many are used) and all broadcast the same thing at the same time... Hence, (Simulcast) simultaneously transmitting... And that can lead to the distortion issue with some radios due to propagation delays
from the various sites...

 

[Baker845]

thank you all for the info. I keep getting told it won't work good or could work fine. idk at this point.

 

[bearcatrp]

Go research your area in the database on this forum. Look at both analog and digital. When looking at digital frequencies, check out the towers in your county and close by counties. If you have 3 or more simulcast towers in your area, the 436 could struggle a little. I have 5 around me and my 436 seems to be doing fine. I think if you want to save a few bucks, get the 436. If it doesn’t work out, sell it on the forum. The ones that get posted for sale don’t last long. I use my 436 mostly when traveling. My SDS200 is what I listen to at home.

 

[hexagon_keyhole]

Go research your area in the database on this forum. Look at both analog and digital. When looking at digital frequencies, check out the towers in your county and close by counties. If you have 3 or more simulcast towers in your area, the 436 could struggle a little. I have 5 around me and my 436 seems to be doing fine. I think if you want to save a few bucks, get the 436. If it doesn’t work out, sell it on the forum. The ones that get posted for sale don’t last long. I use my 436 mostly when traveling. My SDS200 is what I listen to at home.

Agreed!

This is subjective, but what I have found is that if I hook my BCD436HP to my outdoor antenna, it suffers simulcast distortion. With the BCD436HP with its stock antenna side-by-side with the SDS100 with the stock antenna or outdoor antenna, both radios will squawk just about the same time, with the SDS100 coming first.