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Message |
    
Mayor513
Intermediate Member
Username: Mayor513
Post Number: 119
Registered: 3-2002
| | Posted on Saturday, August 05, 2006 - 4:24 pm: | 
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--Hi, all. Does anyone know of a channel mod. for the Uniden Madison (MB8719 PLL)? I think the Uniden Madison and the Cobra 2000 channel mods are the same. I saw a Cobra 2000 on an auction site with low and high channels...the range was from 26.065 to 28.305. Can anyone help with a channel mod.?
--I've got a Uniden Madison coming to me that already had a channel mod. in it, but the frequency range is from 26.825 to 28.045. I would like the frequency range to be a lot lower...at least as low as 26.065. Is it possible to sort of "shift" the bandspread? For instance, instead of 26.065-28.305, perhaps somehow losing one band on the top end, but gaining another band on the bottom end? For example 25.625-27.865? I WILL be having someone else do the mod. for me, haha. Thanks. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1951
Registered: 9-2004
| | Posted on Saturday, August 05, 2006 - 9:49 pm: |
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the only way to get that chassis to go down to 26.065 is with crystal switching, and that method leaves a bit to be desired.
people have noted a warble on SSB transmit when using the crystal switch method.
the 26.815-28.045 range is the standard PLL mod, which is tried and true, and if done right, works well and reliably.
yes, you can custom tailor the freq. range by choosing the right crystals, within limits of course.
you're not going to get down past about 24 mhz with it, and no matter where you put the range, its still going to be 2mhz without heavy modifications to the radio.
all that being said, please allow me to insert my opinion on this.
below channel one, pretty much every freq. down to 25.000 mhz is owned by either the army, air force, or the navy, and with all the military action in the world, you can bet that they are active, even if not very often.
so it could be cool to listen down there when DX is really rolling, but transmitting down there is getting more and more dangerous.
i am not judging, just informing.
also, the receivers sensitivity is quite reduced at that low in the the freq. range, and your chances of hearing anyone are VERY, VERY slim.
these days the only real action is from 27.415-27.535, on SSB.
the reason it stops at .535 is the same reason as below one.
staying off of the military freqs. is simply self preservation. also the FCC owns some freqs. up there.
so anyway, yes it can be done, but you'd have more fun with a shortwave receiver in my opinion.
matt
PS, if you want to look into the crystal switching method, do a google search for lou franklin and CB city international. |
Ferd_burfell
Junior Member
Username: Ferd_burfell
Post Number: 18
Registered: 6-2006
| | Posted on Monday, August 07, 2006 - 9:04 pm: |
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"these days the only real action is from 27.415-27.535, on SSB.
the reason it stops at .535 is the same reason as below one. staying off of the military freqs. is simply self preservation. also the FCC owns some freqs. up there. "
That's never stopped anything. Your radio's aren't able to perform properly that far down. 26.815-28.045 is indeed the natural easy conversion. Accept it & move on. If you insist on having more, just get anything like an export radio that goes real low. It's not always right to turn a silk purse into a sow's ear - the BANE of CB'rs |
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