148 gtl mod help

[Steve Hurst]

Hope I am posting in the right place. I have a Philippines made cobra 148 gtl with a mb8179 pll chip. It has had the pll crystal (big one center front of board) removed and wired to a 3 position switch with 2 crystals 11.1758, 11.4758 plugged into it and other things done to make what ever they were doing work. Can some one show me a link to what has been done so I can remove it, one side of the switch doesn't work. It looks like a hack job and the wires move around and it seems to cause frequency drift. I like to possibly find diagrams or directions I can look at to figure out what has been done so I can remove it, or at least the mod name so I can google it, I am having no luck. Thanks

 

[nomadradio]

The most common kit of this type required that you remove the factory-original 11.325 crystal and put it in the empty socket on the kit. Removing it from the kit, removing the kit's two wires to the radio circuit board, and putting the 11.325 crystal back into those two holes is the starting point.

Good chance the radio won't be exactly on frequency now. The added wiring of the kit will change the settings of L23, to set the clarifier for 12 o'clock at the center of channel for AM only, L22 for LSB and L59 for USB.

And if the radio has been modded to "stretch" the clarifier to cover a wider frequency range, these three coils may or may not set properly with the clarifier knob at the 12 o'clock position.

73

 

[loosecannon]

for that modification, all they do is remove the crystal, and solder the switch wires in its place.

unsolder the wires from where the crystal used to be, and put in a 11.3258mhz crystal.

then re-align the radio and it should work.
LC

 

[sonoma]

more than likely it is the expo L kit that was made to get upper and lower channels on this radio. most people would kill to get that done to their radio so they could talk on the upper channels to get away from the regular cb channels. those kits are very rare and hard to find since they are not made any more. why would you want to remove it since it is installed and working. every 8719 PLL units I have this is in all of them . I have a couple radios that I do not have one in them since I have not been able to buy the kit. had to expand the 8719 to get some upper channels I like to run on. the kit you have gives you 40 channels up and 40 down.

 

[sonoma]

one item I forgot to mention if you pull the mod out you will need all the proper equipment to realign the radio such as a freq counter and a watt meter and a scope and the know how to use the equipment. you may make the radio where you can not even talk on it any more if not aligned properly. you can not just pull it out and think it will work as it should.,
Nomad basically already told you this info.

 

[sonoma]

here is some info as to installing the kit. this will give you an idea as to what it would take to reverse the mod. now this is just the basic install. some other items may have been done also. you stated one side of the switch is not working. have you tried cleaning the switch for the kit. may just be dirty. who ever installed it may not have known how to install the kit properly.
so many variables in this item that could be the problem.

http://www.cbtricks.com/miscellaneous/vco/expo/model_l.htm