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Frankenstein 148GTL

mechanic

mechanic

Well-Known Member
Mar 4, 2009
596
126
53
North coast of the USA.... Da UP!
I have been working on a project radio recently, A Cobra 148GTL and I do not know the history on it. Bought it two years ago at the Dayton HAM fest. On the last day and I had not bought any rigs so I came across the flea market booth. Wanted 45 dollars so I talked him to 30, brought it home and it was junk!
Disgusted I stowed it away and recently found it again! What a piece of junk!
Thinking of the thirty dollars and how much beer it could have bought, I started tinkering with it.... well it needed lots of TLC.... S/RF meter shot, wires all over, a goofy Expo 100 crystal kit replacing the SWR switch, broken slugs in the IF cans! Bent shafts, beat up front panel, What a piece of junk! And I forgot what "caveat emptor" means! :oops:
Since I cannot beat myself too much I decided to part out a dead 148 and I have an old Washington, all to donate parts.... 6 hours later it was up and running! pulled all the junk out and replaced the meter with a good one! Looks good now and just some final peaking, it's doing 20 watts SSB and 3 watts dead key with 8 watts swing on AM! Also hav 5 up es down on the voice lock! (Strange MOD) :confused1:
Not a piece of junk anymore and as soon as the stitches heal, I do not think any one will notice the bolts in the neck!

73 mechanic
 

the wide slide was to cover the "a" channels back in the day, thats how you modded 148's 15-20 years ago. the 10k swich wasnt really well known back than as the cb mod books did not have it listed. as you know it absolutly destroid ssb use. it was the origional opened clairifier, it still gets me when people say the clairifier is opened on a radio, i believe the correct term now would be married not open.

with such a wide slide its really touchy to get even close to frequency with them.

thank god for the internet and the sharing of knowlage we have now. i cant tell you how many of those butchered 148's ive come aross in my days of playing with them. unfortunaly finding a virgin 148 these days is like finding a real 16 year old virgin, its not going to happen very often.
 
The slide is not bad at all and pretty even across the range. USB is off from AM / LSB, with them at 12 o'clock, USB will be at 1:30 for center. TX and RX track right with each other! :mellow:
I do agree the most slide mods are garbage and tricky to get them to work I had a PC 122 years ago and swapped out the PLL to get 40 more, bad thing was that the fo's would end in zeros. Had to add a "super diode" to get the fives! Those were the days! :oops:
Now I would do it with a DDS circuit but not worth the effort anymore! :lol:

The 148 has turned out well! I just changed out the display as there missing segments, just about done! :w00t:

73 mechanic
 
Audio I actually still have one of those damn 10 turn pots!!!! It was in an older Galaxy Saturn I had that I put back to stock.

Mechanic .....even after retuning the VCO adjustments the clarifier could not be set at 12:00 on all three modes??
 
ohh the 10 turn's. took about a good 20 seconds worth of spinning.
 
TonyV225 said:
Audio I actually still have one of those damn 10 turn pots!!!! It was in an older Galaxy Saturn I had that I put back to stock.

Mechanic .....even after retuning the VCO adjustments the clarifier could not be set at 12:00 on all three modes??
Click to expand...

I do not normally "goof" with the frequency adjustments on most radios but the "Frankenstein 148" was in tough shape, the output IFs all had cracked or broken slugs. The clarifier was center at almost 4 o'clock, so after changing out the broken slugs and getting it to being close to transceive, I adjusted L59, L22 and L23 to bring the voice lock back towards 12 o'clock. USB would not go there, only to 1:30 even adjusting CT2 would not bring it around. :confused1: I did not try VR5 and may try that yet.
I left the open clarifier, BTW

73 Mechanic
 
Last edited:
well you can't really blame them for using the 10 turn pot when they wanted to get the zeros because the wiring wasn't there to use the dual pot. trouble is with them you wouldn't know where you were transmitting from looking at the knob. I found a 3 turn pot on a crown portable tv that looked the very same as a dual pot but it was a single and the inner shaft was geared to the outer pot. It would slip when it the shaft was fully rotated but at least by looking at the outer knob you would know where you were transmitting. I often wondered why they were not used for that purpose instead.
 
mechanic said:
I have been working on a project radio recently, A Cobra 148GTL and I do not know the history on it. Bought it two years ago at the Dayton HAM fest. On the last day and I had not bought any rigs so I came across the flea market booth. Wanted 45 dollars so I talked him to 30, brought it home and it was junk!
Disgusted I stowed it away and recently found it again! What a piece of junk!
Thinking of the thirty dollars and how much beer it could have bought, I started tinkering with it.... well it needed lots of TLC.... S/RF meter shot, wires all over, a goofy Expo 100 crystal kit replacing the SWR switch, broken slugs in the IF cans! Bent shafts, beat up front panel, What a piece of junk! And I forgot what "caveat emptor" means! :oops:
Since I cannot beat myself too much I decided to part out a dead 148 and I have an old Washington, all to donate parts.... 6 hours later it was up and running! pulled all the junk out and replaced the meter with a good one! Looks good now and just some final peaking, it's doing 20 watts SSB and 3 watts dead key with 8 watts swing on AM! Also hav 5 up es down on the voice lock! (Strange MOD) :confused1:
Not a piece of junk anymore and as soon as the stitches heal, I do not think any one will notice the bolts in the neck!

73 mechanic
Click to expand...

Do you want to sell that Expo 100 crystal kit? Never heard of a franklen 148 :)
 

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