FM frequency overlap at 27.0-27.9

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battleground
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FM frequency overlap at 27.0-27.9

Post by battleground » Sat Apr 17, 2021 8:21 am

Does the FM frequency overlap on WW2 radios at FM 27.0-27.9 mean that WW2 Armor and Artillery units could communicate with each other directly?

For example, would it be possible for an SCR-508 in an M4 Sherman tuned on FM 27.3 to communicate with a neighboring SCR-610 in an M10 Tank Destroyer tuned to FM 27.3?


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Re: FM frequency overlap at 27.0-27.9

Post by John Neuenburg » Tue Apr 20, 2021 6:00 pm

I'll let a radio expert answer but want to add that the SCR-608 and 628 sets run at 27-38.9 MC. My guess is it's as simple as plugging in crystals between 27 and 27.9 in all sets so one or more of the pushbuttons allow talking to everybody.

But I don't even know enough about these things to be considered dangerous!
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Re: FM frequency overlap at 27.0-27.9

Post by battleground » Wed Apr 21, 2021 12:56 pm

Yes, I agree that it seems possible and likely but am also not an expert. Hopefully someone will confirm that this would or could work. Even better would be some knowledge that this overlap was intentional.

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Re: FM frequency overlap at 27.0-27.9

Post by Radtech » Thu Apr 22, 2021 4:29 am

The units overlap only at 27.9

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Re: FM frequency overlap at 27.0-27.9

Post by John Neuenburg » Thu Apr 22, 2021 9:17 am

Radtech wrote:
Thu Apr 22, 2021 4:29 am
The units overlap only at 27.9
Don't the "tank" radios go 20- 27.9 and the "artillery" radios start at 27? Aren't there crystals between 27 and 27.9?

Related question is are the sets identical otherwise and so would a 20 or 25 MC crystal work in an "artillery" radio?
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Re: FM frequency overlap at 27.0-27.9

Post by Radtech » Thu Apr 22, 2021 8:42 pm

SCR 508 is 20-27.9.SCR 610 is 27.9-38.5.They ONLY OVERLAP at 27.9.

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Re: FM frequency overlap at 27.0-27.9

Post by YLG80 » Thu Apr 22, 2021 11:43 pm

Radtech wrote:
Thu Apr 22, 2021 8:42 pm
SCR 508 is 20-27.9.SCR 610 is 27.9-38.5.They ONLY OVERLAP at 27.9.
I thought that the SCR-610 was covering the 27 Mhz ( not 27.9 MHz) to 38.9 Mhz. :?
So there would be a frequency range overlap from 27 to 27.9 Mhz with the SCR-508 and complete overlap with the SCR-608.
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Re: FM frequency overlap at 27.0-27.9

Post by g504 » Sat Apr 24, 2021 2:27 am

Hello.

For information.
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