BCD396XT/BCD996XT: Motorboating on analog frequency? Didn't know it could...

[fatboy_dan]

I'm very familiar with motorboating on digital frequencies (mostly with my SDR stuff) but a known NFM frequency for tribal police (my general area) has pronounced 'motorboating' on that frequency, and the dispatch that goes along with it, UNLESS signal is over 75%. There's a slight delay, then this issue occurs. This is on a BCD996xt. My handheld, a BC75xlt does not do this, nor does my BCT15X, or any of my retired rigs. Being that my 996 is my main feed rig, I need some information or clues into solving the issue for feed listeners and my own peace of mind. Any assistance would be extremely helpful, thank you!

 

[tvengr]

Motorboating can be caused by poor power supply regulation. Try a different power supply.

 

[fatboy_dan]

Motorboating can be caused by poor power supply regulation. Try a different power supply.

Thank you, I tried that. It did help some switching to another, however the effect is still there on one frequency. I'm beginning to suspect it's something on the broadcast end. I just... can't prove it.

 

[nessnet]

By "motorboating" are you referring to a low frequency 'thrumming' sound..?

Is the system a Motorola Type II SmartZone per chance?

 

[fatboy_dan]

By "motorboating" are you referring to a low frequency 'thrumming' sound..?

Is the system a Motorola Type II SmartZone per chance?

Yes, thrumming and a sound like it's underwater (reference, the sounds a go-pro or similar action cam pick up while submerged) at weaker reception levels. I did manage to get the situation to repeat on other rigs but not on other frequencies. Probably tried 3 or 4 times, with different methods to both eliminate, and reproduce the effect to find an educated guess on cause. Could also be like the old cassette tapes with 'noise reduction' that sounded muffled, but not quite.

System is, according to FCC emission designator:

11K0F3E--
Bandwidth: 11.0 kHz
Modulation Type: [F] Angle-modulated, straight FM
Modulation Nature: [3] Single analog channel
Information Type: [E] Telephony, voice, sound broadcasting
Modulation Type Notes: F3E FM speech communication – often used for marine radio and many other VHF communications

And the particular tower that I pick up this runs 3 frequencies , two of which... 155.085 and 155.775 respectively do this. The latter is more constantly doing it however .085 is doing it as well. No other frequency used by the agency does, not even tac channels. No agency within range of the scanner including their repeaters do this either, only those two frequencies... and mainly only on my 996xt. I can get the 15x to reproduce the same effect but to a much lesser extent and I have to almost force it to by oddball settings via arcXT

 

[nessnet]

What system is this??
(Link to the RR page will suffice...)

 

[KevinC]

What system is this??
(Link to the RR page will suffice...)

I'm guessing this...

Tribal (Washington) Scanner Frequencies and Radio Frequency Reference

Scanner Frequencies and Radio Frequency Reference for Tribal (Washington)

www.radioreference.com

 

[nessnet]

These are the users of 155.085 in WA

RR Database Home

The most complete database of radio communications data

www.radioreference.com

Search Results for 155.085 in (Washington)

Freq Out Freq In Tone Callsign Description Category Agency/County State
155.08500 WPZR413 LTAC County Wide Special Operations/Tactical Channel Law Enforcement
Cowlitz County Cowlitz
WA

155.08500 KBV868 Public Works Elma
Municipalities Grays Harbor
WA

155.08500 91.5 PL Mabton Fire / EMS
Yakima County Yakima
WA

155.77500 155.08500 (Freq in) 131.8 PL WPZK718 Police Dispatch Public Safety
Colville Confederated Tribes Tribal
WA

 

[fatboy_dan]

Sorry, I'm doing many things at once and not able to clarify quickly. Correct in that it is Colville Confederated Tribes Tribal. I was unaware that specific location was needed.

 

[KevinC]

These are the users of 155.085 in WA

RR Database Home

The most complete database of radio communications data

www.radioreference.com

Search Results for 155.085 in (Washington)

Freq Out Freq In Tone Callsign Description Category Agency/County State
155.08500 WPZR413 LTAC County Wide Special Operations/Tactical Channel Law Enforcement
Cowlitz County Cowlitz
WA

155.08500 KBV868 Public Works Elma
Municipalities Grays Harbor
WA

155.08500 91.5 PL Mabton Fire / EMS
Yakima County Yakima
WA

155.77500 155.08500 131.8 PL WPZK718 Police Dispatch Public Safety
Colville Confederated Tribes Tribal
WA

He mentions "tribal" and his location is "Grand Coulee", so that's why I picked the one I picked...but I could be wrong.

 

[fatboy_dan]

He mentions "tribal" and his location is "Grand Coulee", so that's why I picked the one I picked...but I could be wrong.

Actually you're spot-on. I wrangle a lot of things at once, I'm sorry if I'm not always precise. Two regional fire watch groups with tens of thousands of members between them gets tricky fast, 4 kids at home and the usual day to day stuff occupies too much brain capacity I suppose

 

[fatboy_dan]

It may be worth noting I suppose that the CCT (what they call themselves in official means for public safety and other official matters) tribal frequencies I receive are the only ones that are not via repeater or direct line of sight. There are no power stations or major RFI/EMI sources between myself and the source towers either. The situation seems to have cleaned up, however now I'm faced with a mystery as to why it did this in the first place... and I want to solve it.

 

[KevinC]

Are you using the PL or carrier squelch?

 

[fatboy_dan]

Are you using the PL or carrier squelch?

Not using CTCSS or other similar squelch method, and the front knob is only set to 1.

 

[nessnet]

He mentions "tribal" and his location is "Grand Coulee", so that's why I picked the one I picked...but I could be wrong.

You read (saw "tribal") better than I did......

It is:
Police Dispatch Public Safety - Colville Confederated Tribes

 

[KevinC]

Not using CTCSS or other similar squelch method, and the front knob is only set to 1.

I wonder if the PL is actually DPL (which "rumbles" sometimes). Someone may have seen the "turn-off" code flash (it will show either 131.8 or 136.5) and thought that was the PL.

Maybe try the PL of 131.8 and see if you still hear them. This is just a WAG though.

 

[12dbsinad]

You could be hearing localized RFI on particular frequencies. Try things like killing all power while running off a battery.
Secondly, they wouldn't happen to be running a analog simulcast system are they?

 

[fatboy_dan]

You read (saw "tribal") better than I did......

It is:
Police Dispatch Public Safety - Colville Confederated Tribes

Officially it is labeled dispatch however it's police primary as well. as is 155.085 and a few more not listed via RR. I think it depends greatly on which district they're aiming for (CCT has four) and more particularly, which unit/division within it.

 

[fatboy_dan]

You could be hearing localized RFI on particular frequencies. Try things like killing all power while running off a battery.
Secondly, they wouldn't happen to be running a analog simulcast system are they?

I'll try that. No simulcast. Only simulcast nearby is in the 800's and a totally different agency. Honestly their stuff isn't that advanced, I mean, heck, the reservation just got fiber trunk for digital anything online a year ago.

 

[fatboy_dan]

You could be hearing localized RFI on particular frequencies. Try things like killing all power while running off a battery.
Secondly, they wouldn't happen to be running a analog simulcast system are they?

I have a setup I made just for doing things like that while off-grid. I will try it for this purpose and let you know