BCD536HP vs BCD996XT sensitivity?

[VASCAR2]

I have a Friend in the Quad Cities area (Davenport, Bettendorf, Moline, Rock Island) having issues with his BCD536HP. He’s using his 536 to monitor RACOM system which is a multi site trunked EDACS system. His 536 scanner receives static in the transmissions like there is electrical interference from an electrical transformer. The interference is worse if he connects his scanner to a Discone antenna mounted at 30’ outdoors. The interference is only detectable on the RACOM 800 analog system and not the VHF Hi or P25 Starcom 21 Illinois trunked system.

We’ve been trying to isolate the issue and have eliminated the source as being from the electrical grid. I went to my Friends house with my BCD996XT and connected my 996XT to his discone antenna. My scanner did not have the same noise/interference/static as the 536HP. Sitting in the same room with the pull up supplied antennas the reception was the same between the 536HP and my 996XT and neither experienced the interference/static.

My scanner operated perfectly on the outdoor discone antenna and as is predictable had increased range and signal strength. We connect his 536HP to the Discone antenna and the noise/static returns. One disadvantage with the 536HP is you can’t easily determine which site is being received. We’ve tried avoid/locking out sites but can’t determine if the Discone is picking up distant sites that give poor reception or if the front end of the scanner is overloaded by the close proximity to sites and the Discone signal is just to strong on the 536HP. I turned on the attenuator which made no noticeable difference.

Seems strange my BCD996XT worked perfect whether with the supplied pull up antenna or Discone antenna whereas is 536 is only useable on the pull up antenna. My Friend likes the Discone antennas as it gives the extended range to receive VHF local agencies and Iowa State Police.

I thought about trying a line filter but since my BCD996XT works I can’t see where a filter would help. Does the BCD536HP have more sensitivity or is this a case where two different scanners have different capabilities or quirks? Would an RF filter on the discone antenna coax make a difference?

Another strange issue is if we go into the BCD536HP menu and temporary avoid or permanent avoid sites the sites still showup on the display while scanning. It is difficult to determine if the site has been locked out/avoid. Will a avoid site still show up on the display while scanning? I know you can try to stop on the site control channel but the noise associated with EDACS control channel is rather annoying. Not really fun to try and check each of seven sites to determine if they are temp. or perm. avoid.

My Friend used Sentinel Software to program his scanner.

I know radios and scanners have unique characteristics but this is a head scratcher. I suggested my Friend add Quick Keys to the different RACOM sites to see if the interference/static can be traced to more than one site or is it on all sites. With the Quick Keys he could easily avoid different towers if the signal has interference/static. If he finally gets a clear signal with no static he could then check the control channel frequency. Prior to getting me involved in tyring to find the cause my Friend had all RACOM sites in the Quad Cities area in the scan menu with none locked out/avoid.

I’m open to any thoughts or suggestions. I’m afraid my Friend might be forced to only use his pull up antenna unless someone has any ideas.

 

[VASCAR2]

I can’t see how to edit my original post so I’ll add some additional info on the 536HP. At different times of the day/night the 536 will have the static even with the pull up antenna. The static/interference is always worse with the Discone antenna. Could this be a hardware issue where there is a component starting to fail inside the scanner? Seems odd this static is only present on analog 800 Mhz.

The one time I had my BDC996XT next to the BDC536HP the static wasn’t very noticeable. I can’t find any relation to an outside source that could be causing the interference (powerful radio station, electric power sub station or other common culprits). The Electric Utility company tested their infrastructure in the neighborhood and found no failures or noise inducing components . We can not correlate the static to any environmental factors.

 

[Ubbe]

You can use Siren with an old Android device (iPhone don't work) to see what sites the scanner use or Unidens RH-536HP software will also show sites.
http://info.uniden.com/twiki/pub/UnidenMan4/BCD536HPFirmwareUpdate/RH-536HP_mkII.zip

Try to set IFX to the frequencies that have the static problem.
Could you make a recording to listen to as that might give an indication of what type of interference it is. RF interferencies cannot be heard on digital systems. If you set the bandplan to AM mode you could enter a frequency by CHANNEL+Freq+CHANNEL on the keypad and tune around and listen to any abnormal interferencies. It should only be a soft noise, much like the same you hear without any antenna connected.

/Ubbe

 

[VASCAR2]

Thank you for the reply. We have a recording of the static on the audio, I’ll try to get it posted. I had considered entering the frequencies as conventional in their own favorites list. I also considered entering some of the mobile encode frequencies as conventional frequencies to see if the static was present. It just seem strange the higher 800 frequencies seemed affected and not the lower VHF.

That is a good idea to enter the frequencies as AM and check for interference. One of my Agency radio techs found an isolator bad on a utility (electric) pole not far from one of our towers. He used the AM radio in his work van and started driving in the area. The generated static was affecting the sensitivity of the receiver on our VHF Lo band.

I was reading some previous threads regarding issues with the BCD536HP and saw Siren software mentioned. I’ll check into the Uniden software you listed. Thanks again for the suggestions.

 

[VASCAR2]

Trying to upload audiovideo no luck yet.

 

[tepping1]

You can use Siren with an old Android device (iPhone don't work) to see what sites the scanner use or Unidens RH-536HP software will also show sites.
http://info.uniden.com/twiki/pub/UnidenMan4/BCD536HPFirmwareUpdate/RH-536HP_mkII.zip

Try to set IFX to the frequencies that have the static problem.
Could you make a recording to listen to as that might give an indication of what type of interference it is. RF interferencies cannot be heard on digital systems. If you set the bandplan to AM mode you could enter a frequency by CHANNEL+Freq+CHANNEL on the keypad and tune around and listen to any abnormal interferencies. It should only be a soft noise, much like the same you hear without any antenna connected.

/Ubbe

so the ongoing static problem is specific to RACOM which is 90% of what I monitor but not specific or discriminate as it happens on every operating frequency they have no matter what agency....the static makes it impossible to hear the transmission, however if I quickly grab the silver knob and flip it so it will rescan, it will land right back on the same agency(assuming they are still in the midst of that transmission) that was transmitting in unledgible static to a perfectly clear reception within a mili second and it will work everytime....your thoughts on what could cause that?

 

[Ubbe]

When you receive the transmission from one site, buth not the other, you have that problem so lock out that site. It's either interfered or too weak or the frequencies of that site use simulcast and are reused on another site with the same signal strenght.

/Ubbe

 

[tepping1]

When you receive the transmission from one site, buth not the other, you have that problem so lock out that site. It's either interfered or too weak or the frequencies of that site use simulcast and are reused on another site with the same signal strenght.

/Ubbe

let me make sure I am clear....turning on a site or locking out(permanent avoid) or turning on/attentuation on or off..... ALL of that has been tried with every possible combo(I wrote down every possible combo) of the 8 sites from the closest which is 3/4 of a mile to the furthest at 15 miles. None of the towers matters. On top of that I have tried the telescopic, Discone at 30' and 2" stubby with ALL possible pairings and it doesn't make a difference. VASCAR 2 has actually been here and experienced this...he's stumped as well

 

[Ubbe]

....if I quickly grab the silver knob and flip it so it will rescan, it will land right back on the same agency(assuming they are still in the midst of that transmission) that was transmitting in unledgible static to a perfectly clear reception within a mili second and it will work everytime....your thoughts on what could cause that?

You really have to use some sort of indication of what sites you are monitoring, using Siren app or RH536. If it actually scans back to the exact same site and use the same frequency then we are all stumped and you have an unexplained problem. I'm convinced that it all will be clear when you display site and frequency while listening.

/Ubbe

 

[tepping1]

Ubbe...thanks for your replies....when I first got the 536 back in the spring...the Siren connected fine....had to go to Florida for some health issues/ treatment...returned in Sept and I cannot for the life of me with updates get the app to reconnect..just shows "no scanner found"....I have great signal strength, my own router and modem....yes it would be interesting to compare what freq may be the culprit

 

[tepping1]

I cannot find on this forum or in the manual whether the 536 processor is capable of the following: configure tower sites to one favorite list that would be different on a 2nd favorites list? I doubt if that's possible but I thought I would ask

 

[Ubbe]

In the left pane in Sentinel you right click on that system and select to append to a favorite list and you choose another fav list to copy to. Then make permament avoids on the sites you do not want in respective fav lists. Or set quick keys for the sites. Selection are 3 digits Favlist.System.Site but could be a bit more confusing than setting permanemt avoids.

/Ubbe