Icom R7000a & R9000 MOD. FOR NARROW BANDING

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IdenLarry

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Fellow Forum Members,

Does anyone have a modification for FM narrowbanding for these receivers? With the new regulations going into effect in 2013, I'm sure this will be a popular subject.

Thanks,
Larry
 

kruser

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St. Louis County, MO
Fellow Forum Members,

Does anyone have a modification for FM narrowbanding for these receivers? With the new regulations going into effect in 2013, I'm sure this will be a popular subject.

Thanks,
Larry
Both models already have a 6.0 kHz filter. Just select the FM Narrow filter.
For the R7000, the FM switch on the rear panel needs to be set to FM1 (I think) which will allow the front panel buttons to select a 15 or 6 kHz filter width. If the rear switch is set to FM2, the front panel buttons will select a 100 or 15 kHz filter. The R9000 has all three filter widths available from the front panel already.
For FM mode, Wide position = 100kHz? Middle = 15kHz and Narrow = 6kHz

When everything goes even tighter to the 6.25 kHz bandwidth, then tighter filters may be needed if you have co-channel interference but they should handle the 2013 mandated 12.5 kHz bandwidth just fine as they are.

Many of the systems here have already switched to 12.5 kHz radios and my R7000 and 9000 receive them just fine with no co-channel interference from the new neighboring channels that are on some of the new narrowband frequencies.
The only problem I am seeing is some of the radios that have been switched to 12.5 kHz are off frequency. Those radios will bleed into the new narrowband channel above or below the old wide band channel depending on which way the radio is off freq.
These same mobile radios were off frequency before they set them to 12.5 kHz. I would have thought the radio techs would have looked at that when they switched them over to narrow but I guess I thought wrong.
They must have just plugged the programming cable in and switched the bandwidth but never bothered to actually check the radio for proper frequency and modulation.
Some are so bad that I cannot see how the dispatcher can understand them unless the dispatch radio is still receiving in wide bandwidth. When those mobiles talk, I must switch the 7000 or 9000 to 15 kHz in order to understand the mobiles. Usually they do not even open the squelch though unless they are very close so I never know they are talking unless I also have a wide mode scanner running.
 
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