146.6875 out / 146.0875
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Actually,taking a closer look.
146.6875 / .0125 = 11735.0
146.0875 / .0125 = 11687.0
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Are even integers, so a 12.5 KHz? (and 6.25 or 2.5 KHz) radio will do it. Still some older Part 90 VHF radios may not. But if the model/brand was used on Federal VHF, it may work.
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On Mon, Mar 17, 2025 at 08:12 AM, n3ltq wrote:
As you are no doubt finding out, the average ham radio has 25kHz IF
filtering and +/- 5kHz (or more) TX deviation with little or no
modulation limiting.
Your choices for equipment that can resolve to 2.5kHz channel steps
will be limited.
Quoting "TIM HARDY via groups.io" <w7trh@...>:
Hi folks,
I'm in Wa. state and WWARA has authorized me a NB rpt. pair 146.6875
out / 146.0875 in. (2.5 kc / 12.5 kc ch. spacing)
My rpt. is a Motorola Quanter.
I now am searching for compatible radios that will operate on the
"splinter" fxs.
The radios must have the proper "IF" filters on rec. for NB.
I have heard that the Motorola CM300 "May" be usable for NB use.
I have a few Mot ASTRO Spectra mobile trunk mount radios. I have
read that if they are labeled "2.5 kc" they may be usable.
I have not checked the Astro Spectra radios yet. (FCC id #)
Any ideas of compatible radios for me to tell our radio club about?
(So they can utilize the rpt...LOL)
I appreciate any guidance or transceiver advice.
Tim
AE7TH
Vashon Is. Wa.
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--
The Real RFI-EMI-GUY
RFI-EMI-GUY