BCD436HP vs. SDS100 Missing Transmissions

N3BQX

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I’ve programed my BCD436 and my recently purchased SDS100 with the same Sentinel software profile so that the programing should be identical. I am monitoring Illinois State Police District Chicago on only one site, Cook North / NWCD Simulcast Site on both radios. The SDS100 misses many of the transmissions that the BCD436 picks up. For example, I will hear both dispatch and base clearly on the BCD436, but often only one side on the SDS100.

I’m on an upper floor of an apartment building and using a Comet SMA501antenna on the BCD436 and a Remtronix antenna on the SDS100. I’m not able to swap the Comet on the SDS100 because it won’t fit, so I’ve compared both with the antennas removed and the reception problem is the same.

The only thing I can think of that could explain this is that RatedRadarDetector.org states that “The BCD436HP scanner is by far the faster scanner in terms of scan and search speeds…”. Since the SDS100 is supposed to be better than the BCD436 on Simulcast, is scanning speed the problem or something else?
 

trentbob

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So you are talking about the starcom21 phase ll 7-800 MHz system. You're only listening to one site. Technically the 100 should perform better than the 436.

The remtronix Is the preferable antenna. The 100 is a slow scanning radio. I find it helps to keep a system on its own favorites list and not mix it with any conventional stuff. You might want to consider using a different filter other than the normal filter which is the default, could make all the difference in the world with skipped transmissions. If they don't help you can always apply a 2 second system hold time In System options. If you're interested I can walk you through The proper filter application Process.
 

n1chu

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There’s a proper filter application process? I thought filtering was all about location location location, where one filter setting may work for well in one location but not so much In another? Is this process something you could post?
 

trentbob

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I would be glad to explain the process to you. Yes the filters are different for everybody. What works for you won't work for me. It depends on your RF environment. Give me sometime because it will be a long post but I will show you the method that I use. Made all the difference on my P2 system where I was missing Transmissions and what worked for me was wide invert. Standby and I will give you a step-by-step process.
 

trentbob

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Everybody has their own opinion about this but this is the system I use. You do it on the radio so you get real time results. After the proper filter is applied to just your system you then go to sentinel making the target the SDS 100 and transfer the card data to the computer and this will save the changes that you made.

You go to Global filters, Global filters affect every object in the radio and should only be used to sample filters. You don't want to try auto filter as that will slow scanning way down and you already know what normal does. You are going to try the global filter of invert, wide invert and wide normal while you are observing RSSI level, noise level and error rate. Some claim RSSI is not a good indicator but I use it anyway. Just listen for a while and see what helps the skipped transmission. When you find out of those 3, the best filter then return global filter to Normal as that will apply to every object that you haven't gone into Site options or in the case of conventional frequencies Department options and changed. You want global to stay normal because you don't want to compromise any objects that work well on normal.

Drill down on the menu to site options of the system you want to change, apply the filter to your site that you found works best out of the 3 you sampled.

Back out of menu and now you will have that filter just applied to the site that you listen to on your one system you're having a problem with. If you're going to experiment with filters on different objects you might want to add the filter indicator to your display to help keep track. Don't forget to go right to sentinel and transfer the card information To your Profile after you target the SDS 100.
 
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n1chu

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I would be glad to explain the process to you. Yes the filters are different for everybody. What works for you won't work for me. It depends on your RF environment. Give me sometime because it will be a long post but I will show you the method that I use. Made all the difference on my P2 system where I was missing Transmissions and what worked for me was wide invert. Standby and I will give you a step-by-step process.
That would be helpful. Thank you. Standing by.
 

trentbob

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The filters were added later on in 2 firmware updates because of the problem of missing Transmissions. I had actually put the radio in a drawer and stopped using it and went back to my apx7000. I was hoping a remedy would be found and when the filters came out it was like a miracle. Never had a problem again with my hometown Phase 2 system.
 

trentbob

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I'm going to be on and off today here. If you find the filters do not help then you can drill down to system options of your system and apply a 2 second system hold time. This is a drastic measure because it will slow scanning down even more if you are listening to other systems or conventional objects but it will help with missed Transmissions. Sorry with all the capital letters, my auto-correct is malfunctioning LOL... if you do apply a 2-second system hold time remember you will have to transfer that info from your card to the computer to save that change also.
 
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MStep

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FWIW, my own experience is the the 436 and 536 essentially outperform the SDS100 and SDS200 in terms of not missing transmissions, unless, as trentbob has explained, you have the time and patience to fiddle around with the aforementioned filters. But even after spending some time tweaking the filters for various systems, I still have to give the edge to the *36 series. As many will tell you, your mileage may vary.
 

N3BQX

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I will fiddle with it for a couple more days and let you guys know if there is significant improvement. I'm about to take a road trip soon and the BCD436 did fine before with GPS so I might just stay with the 436 for the trip.
 

trentbob

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FWIW, my own experience is the the 436 and 536 essentially outperform the SDS100 and SDS200 in terms of not missing transmissions, unless, as trentbob has explained, you have the time and patience to fiddle around with the aforementioned filters. But even after spending some time tweaking the filters for various systems, I still have to give the edge to the *36 series. As many will tell you, your mileage may vary.
Unless of course you are in a heavy simulcast Distortion area secondary to LSM like my County.. X36 was very problematic with my tdma phase ll system. There were spots in relation to simulcast Towers where it would work but definitely not in a mobile application. My system has one site called simulcast + 26 towers very close together all transmitting the same thing your radio is calling for... It is a simulcast nightmare and the x36 was not usable. It got no mileage on this particular system. LOL.
 

MStep

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Unless of course you are in a heavy simulcast Distortion area secondary to LSM like my County.. X36 was very problematic with my tdma phase ll system. There were spots in relation to simulcast Towers where it would work but definitely not in a mobile application. My system has one site called simulcast + 26 towers very close together all transmitting the same thing your radio is calling for... It is a simulcast nightmare and the x36 was not usable. It got no mileage on this particular system. LOL.
I guess I should have mentioned simulcast, which was not problematic for me due to antenna configurations. I was speaking specifically about missing transmissions.

(For those who may have read it already, I edited out a separate thought I had placed in this post until I can do more research.)
 
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Ubbe

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Don't forget to also include the Off setting in the testing of filters.

Uniden have named the settings very badly and not at all what they do.
The Off setting are actually the normal setting that all scanners use and pass signals +/-5MHz from your monitored frequency.
The Normal setting are a low pass filter that pass 10MHz of lower frequencies but blocks higher frequencies.
The Invert setting are a high pass filter that blocks lower frequencies but pass up to 10MHz of higher frequencies.
The Wide setting are actually a small setting that only moves the filter half way, 3MHz in one direction and 7MHz in the other.
You would want to block the part of the spectrum where you have a transmitter that interfere with reception quality. Usually you will have no idea which transmitter that are the problem and it's a trial and error procedure.

Also try IFX on the frequencies of the site. That can make a huge difference. You can enter those IFX frequencies in the Profile in Sentinel and program the scanner and then do the filter setting testings on the scanner one more time.

/Ubbe
 

kevino

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Thank you so much. I will play around with the filters now and see what happens.
I also have an SDS100 and live in the Chicago burbs. I've found that "wide invert" helps to improve reception of STARCOM21 simulcast sites locally. I've also found that it improves reception of conventional UHF frequencies.

YMMV.....
 

n9lob

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My SDS200 had similar behavior monitoring a single TG on SC last night. Pro96com showed the TG active but the radio was silent (no E used).
Thank you trentbob for your method, I saved your post and will experiment when I have time and see if it helps.
 

trentbob

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My SDS200 had similar behavior monitoring a single TG on SC last night. Pro96com showed the TG active but the radio was silent (no E used).
Thank you trentbob for your method, I saved your post and will experiment when I have time and see if it helps.
I'm sure you know about this but for those who don't, when the SDS radios come from the factory there's only a small default number of service types activated, after your radio is fully programmed it's important to make sure that all service types are turned on.

We have a local fellow in my state who had the radio programmed by Bearcat Warehouse, a few months later he had mentioned that he was never able to hear certain EMS talk groups, we asked him about service types and they were only on the factory default setting, Bearcat Warehouse had never activated all the service types and the EMS talk groups were EMS tac. And that's why he never heard them.
 

N3BQX

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After playing with filters for a day now, it seems that Wide Invert and Wide Normal both have reduced the missing calls. Now my BCD436 is missing some calls - Not sure if the BCD436 has any settings for this.
 

n9lob

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I'm sure you know about this but for those who don't, when the SDS radios come from the factory there's only a small default number of service types activated, after your radio is fully programmed it's important to make sure that all service types are turned on.

We have a local fellow in my state who had the radio programmed by Bearcat Warehouse, a few months later he had mentioned that he was never able to hear certain EMS talk groups, we asked him about service types and they were only on the factory default setting, Bearcat Warehouse had never activated all the service types and the EMS talk groups were EMS tac. And that's why he never heard them.
Service types have tripped me up a few times for sure. This was just occasional missing transmissions.
 
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