Cobra 148GTL

[smalltiredart]

On a Cobra 148GTL with MB8719 PLL,

does anyone know how to get
27.415
27.425
27.435
27.445

????

I believe there is a way, but not sure how to do it.... The standard mod does not cover these channels.....

 

[Switch Kit]

there is way , I have some doc on this but I can't figure out how to copy and paste it for you )-: On my Grant XL it was 3 switches total used. 2 doubles and 1 single switch ,(this mod will basically give you everything the 8719 has to offer as far as I know) and the extra switch was basically just to get those extra freqs' your asking about , but from the way my chip was wired seemed a whole lot different from what you would call the basic freq mod. It used to be on the Grant XL site but that site has been down for a long time now.(that was a great site !!) Wish I could help you here STD , but you bet your a$$ ....it can be done.

 

[Moleculo]

Here's a site with the how-to's on that radio. http://www.cbsite.nl/modif/Cobra/cobra2/cobra.htm You either have to install 3 extra switches, or use 3 from the front....

 

[Switch Kit]

Good deal Mole dude !! to bad they didn't include a freq chart )-: , but that's about it STD !! Im sure there are a few variations of this mod , but I think that should be the mod your looking for ,for those extras you'd like to have.

 

[smalltiredart]

Thank You Mole :!:

Thats the info I needed.....

Thanks also S.W.

 

[psycho]

On a Cobra 148GTL with MB8719 PLL,

does anyone know how to get
27.415
27.425
27.435
27.445

????

I believe there is a way, but not sure how to do it.... The standard mod does not cover these channels.....

The best way is to locate an Expo 100 L kit and have a tech install it. The other method that was posted involves repeat and missed channels plus only a dozen or so lower channels.

 

[321 watergate city]

He only asked for 4 different freqs....

 

[loosecannon]

i have to disagree on the expo kit suggestion.

the crystal switching method is fine for AM only radios, too unstable for reliable SSB use.

i know, i know, im sure there are many of you out there that have successfully done the conversion, or have radios with an expo kit.

im not saying it cant be done; i just dont recommend it for this chassis in particular because you can get just as many channels by doing the PLL mods, and it is much more stable.

the full capacity of the 8719 chip is 192 channels. 26.175 to 28.085. both single and dual conversion receiver versions are capable of this.
must use the floating state of pin 10 to get all channels.

for the general "do it yourselfer", i recommend using one 6 position rotary switch, and buying a freq. counter.

here is the 6 pos. switch mod:
http://www.angelfire.com/fl2/cbradiorepair/148chmod.html
loosecannon

 

[ButtFuzz]

192 channels spaced 10 KHz apart? I must be missing something. With the PLL providing the channel spacing, the 8719 being essentially a straight binary chip can have a max capacity of 2^n-1 channels. This would be 2^7 minus 1 which is 128 minus 1. 127 "channels". I believe the frequency range would be better stated as 26.815-28.085.

This, of course, assumes you aren't switching any mixing crystals. The "floating" part of pin 10 is really a "64 + N for use with the 11.125 MHz crystal, 0=128 + N use with 11.3258 MHz crystal." Thus, it is simply acting to drive the radio "up" 640 KHz unless you switch crystals" The 'channel' capacity of the 8719 is still 127 in either case.

'Fuzz