[ICOM] IC-PCR1500 Signals Drop Out

[Gary P. Fiber]

I would also think as you mentioned a priority channel scan is enabled 
though you also said there was no priority scan enabled..
I suspect the good news is that it happens often so a tech may be able 
to trace to the fault if its hardware like a VCO loosing lock but I'd 
think that kind of trouble would even be more pronounced than what you 
described.

How about when not in scan mode does this happen?
Have you checked your scan settings?
Some Icoms have a listen for 10 seconds then move on type of scan, you 
sure you did not enable that type of scan accidentally?

It would seem to me a filter width of 6 KHz is a bit narrow. For analog 
FM the typical audio deviation is + / - 5 KHz
which generally dictates a filter bandwidth of 15 KHz. Narrowed audio 
deviation like + / - 2.5 KHz you would get away with a receive filter of 
7.5 KHz or so.

I have never used a PCR-1500, I have only played with a PCR-1000 
received and its been 10 years ago at that.
I do remember we had a few RP-1510 2 meter repeaters come in with 
European receiver boards.
To that end they had much narrower crystal filters than the normal 15 
KHz ones so the receive audio would clip out of the received bandpass at 
times.

Gary K8IZ



On 6/24/2010 2:00 PM, Terry Schieler wrote:
> I have an IC-PCR1500 receiver that has worked well for years installed in my
> Jeep. Recently I have noticed that during Memory Scan, transmissions just
> drop out in the middle of a dispatch. It is like the radio has lost its scan
> and moves immediately to the next active channel. No delay.  The drop seems
> to occur well into a transmission. Almost predictable in timing.
>
> I checked the antenna and speaker for intermittent connection and both
> appear fine. This is not vibration related as it occurs when the vehicle is
> parked as well. I thought it might be audio initially, but then I noticed
> that the S-meter bar graph totally disappears when the voice drops out. So
> the signal is somehow going away momentarily. This happens on more than 30
> VHF-FM channels and with killer signals as well as marginal signals. I
> checked to assure that there was no Priority Channel assigned and there is
> not.
>
> I recently had removed the unit from the Jeep to program in two additional
> channels. No other programming changes were (intentionally) made. The filter
> width on the VHF-FM channels is set at 6khz.
>
> Any known history of this problem with this particular receiver? Any ideas
> on further testing? Thanks!
>
>
>
> Terry, WØFM
>
>
>
>
>
>
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-- 
Gary P. Fiber K8IZ
Electronic Communications Systems Technician - Field
General Radio Telephone Operators License PG-19-6691,
  with Shipboard Radar Endorsement.
Washington State Resident.