Batboard

I have a Spectra Systems 9000 VHF unit presently installed in my car. The problem I'm running into is with programming in the new frequencies that the FCC allocated inbetween the existing ones. The older Spectra doesn't allow for them to be programmed into the codeplug. Is there a way to bit bang the codeplug to allow for the programming of these new channels that keep popping up? Any advise would be greatly appreciated.

Your probably talking about splinter channels. The firmware the radio has will not allow the internal computer to be set to these channels.

Just another example of how Motorola forces people to throw away their perfectly working radios for the need to do more. As such these older radios are no longer supported. This is the new wave of making more money on their dwindling customer base.

Jim

KC2NNS wrote:I have a Spectra Systems 9000 VHF unit presently installed in my car. The problem I'm running into is with programming in the new frequencies that the FCC allocated inbetween the existing ones. The older Spectra doesn't allow for them to be programmed into the codeplug. Is there a way to bit bang the codeplug to allow for the programming of these new channels that keep popping up? Any advise would be greatly appreciated.

I thought the new splinter channels were all the new 2.5 KHz deviation narrow band. I know some Spectra UHF radios were narrow band, but I do not think there were very many or possibly any narrow band VHF Spectra radios (this is Spectra, not Astro Spectra).

A 5 KHz deviation Spectra on a narrow band frequency would not be legal for Tx. The shape of the bandpass on a 3000 Hz splatter Tx filter is at the wrong cutoff frequency and is does not cutoff sharply enough. So, you can not just turn down the deviation from 5 KHz to 2.5 KHz on a wide band analog Spectra and really be legal. You would need to replace the splatter filter with a 2500 Hz cutoff filter that has the correct bandpass shape.

While there is nothing illegal about a 5 KHz deviation bandpass on the receiver, it is not selective enough when adjacent narrow band frequencies are in use. You will get Rx audio garbage from these adjacent frequencies. These do not make good narrow band scanners either. This will only get worse as more radios move to narrow band and begin filling up the channels.

Everyone here knows the games Motorola plays with their product lines, but I think this is a case of the FCC changing the rules long after these radios were designed and built. In fact, if using the transmitter was in the plans, it is remotely possible that not being able to program a splinter frequency into an old wide band radio may have saved KC2NNS from some deep s**t. I would not be in a good mood if I found an illegal Tx signal was messing with my narrow band radio system.

You could make a Franken radio using a UHF narrow band RF board parts. I'm not sure if the FCC would approve and now we know what Motorola thinks of Franken radios