How to unhack a General Lee HP40

[2FB327]

That's right, how to unhack a nice radio. It has the Ranger 360015c board in it, I searched cb tricks and found some similar ranger boards and set the bias down, the radio was so hot you couldn't touch it, and set the low and high powrer carrier down.
On the scope the when you add modulation it is way off the scope and sounds beyond dirty.
I noticed TR32 is missing, but may not be required on this model, could someone point me to somemore info or
what the hell they do to the audio circuit to try to clean this one up.
Thanks

 

[LeapFrog]

* Disclaimer: This is generic information not specific to your model.
* This is not my YouTube content, the video belongs to "cbrepairguy".

Check if R228 is clipped, check for any added diode *(inplace of-or in series with r238).
By the mic jack TR32 is a 2SC945P it is needed on this radio, AFAIK also TR53 towards middle rear by R228. (one TR for mic-amp/ALC, one for AMC)

For locking it back down to 10 meters, follow the conversion instructions but in reverse!

@ 1:40 resistors and location can be seen.
http://www.cbtricks.com/radios/general/lee/freq_mod.htm

From your picture I cannot see any "npc diode" or "volted final wire" modifications.
The modifications for Galaxy/Connex EPT36001** series pcb's are done in the "usual places" regardless of the silk screened part designation #'s printed on the board. Some slight differences can be seen between EPT360011 all the way up to the EPT360015 series but give or take a few parts (SSB option or earlier bi-polar models) and changes to the board it is still basically the same animal.. Now the RCI-2950 has some more differences..

So all the oldschool export mods should be looked for inside this radio, if you find an older Galaxy mod online, it could have been done to your radio; search for the common mods found online and compare them against your radio. Your model has a built in linear, from what I gather.. Modifications may have been performed to the PA deck, I can only suggest to look for out-of-place/non-factory solder or compare against the schematic.

73

 

[Keeter6227]

That's right, how to unhack a nice radio. It has the Ranger 360015c board in it, I searched cb tricks and found some similar ranger boards and set the bias down, the radio was so hot you couldn't touch it, and set the low and high powrer carrier down.
On the scope the when you add modulation it is way off the scope and sounds beyond dirty.
I noticed TR32 is missing, but may not be required on this model, could someone point me to somemore info or
what the hell they do to the audio circuit to try to clean this one up.
Thanks

what did you set the Hi dead key and low dead key to??? I have this radio also when I got it TR32 was taken out had it put back in and sounds way better.

 

[Robb]

To unhack it? First thing is to look at the coils in the back/center of the board and see if they have been spread. If so; then gather them back to a coil shape. This will make the 54mhz filter work, so long as the upright trap tuning coil slug hasn't been removed or altered. If someone retuned that coil; then it might have also made that trap circuit ineffective. If you have access to a ham radio that receives the 6m band (aka-'54mhz'), you can get that adjustment close to correct by seeing a reduction of the signal. If you test the signal on ch 20AM (27.205mhz); then set the ham radio to 54.410mhz/AM. The first harmonic will appear on the radio at that point, so adjust that coil until you can remove as much as you can. Should get you pretty close.

There is a resistor on the board just in front of the coils near a VR control that has either been clipped or clipped with a diode soldered in series. Either just remove the diode and resolder the resistor back, or just resolder the resistor. Or replace if it is not fixable.

Of course, if the AM Limiter has been removed, then replace it with another 2SC945 as LeapFrog pointed out.

If you really want to make the radio talk and not have a nasty output; then peaking the TX coils is really the best solution - JMHO. You may have to also readjust the AMC pot so that you can get all the modulation you can that is close enough to 100% without getting a bad wave form. Test with using a 1khz audio sine wave; not 'auuuuudio-auuuuudio'. Better results will follow when you tune the TX coils and the AMC pot using an audio sine wave (you can find one on line and use your PC/laptop).

Hope this helps.

 

[LeapFrog]

Robb makes an extremely valid point I have overlooked regarding the 2nd harmonic trap.
Screwdrivers tend to "slinky" these coils, or remove the ferrite core from an inductor to show more "power output" on the watt meter, but the output is way off frequency as you may know.

If the 2nd harmonic "TVI trap" has been fooled with, it will take a spectrum analyzer to get it as clean possible. (Also depends on how misshaped the coils are, and if they can be re-formed without replacement.)
A nearby receiver tuned to the 54mHz area (actually twice the fundamental operating frequency) is good idea in a pinch, also an analog TV set tuned to 'i think' channels 2/4 (if tuning for 11) can also "get you by" (even a cheap SDR), but a S.A. is the duck's guts, if you have access to one!

 

[2FB327]

Thanks, yes they were spread.
So is TR 32 the modulation limiter?
I have the correct transistor and will install it and check and correct at R 228.
I have picked up a spectrum analyzer and I am learning how to use it, but I can see this thing is dirty.
Rob, is there a tutorial on how to set 2nd harmonics with a SA the right way?

 

[JoeDirt]

When unhacking radios, I do a visual write down all I can see. Then I google as many mods as I can find. Check the factory schematic vs the said googled mods vs the radio. Try to correct as many of those "online techs mods" that you can find. Then I do a full factory alignment, If you cannot align correctly that is usually a good indication that you missed something and repeat.....lol

 

[LeapFrog]

I have seen the factory have these coils almost halved (Just a small spread but still a tight form not slinky so it almost looked like a coil is bent into a V) with glue on them after alignment. In that case I'd assume the factory had to adjust them in that manner to get the lowest reading.

You adjust for minimum 2nd harmonic, once you have the equipment in front of you it should be clear what you are adjusting and looking for. You can see a "spike on the graph" and adjust accordingly some manuals say at least -55dbm from the fundamental, I think it always depends on the particular radio how low you can get it without the use of a LPF.

 

[2FB327]

Thanks Joe Dirt. I printed what I could find on cb tricks to try to find someplace to start as far as the 3600 board but I'm still not sure which set up to use as far as the alignment.
Let alone the hacks, what ever he did is in the mod circuit, I'll check for the resistor/diode at R228, put in TR32 and go from there.

 

[Robb]

Y'know, I can't find a schematic for this radio. But from what I've seen on the other 3600 chassis and schematics, then TR32 should be the AM Limiter. This chassis has been around for awhile and there have been many variations on this theme.

 

[LeapFrog]

Y'know, I can't find a schematic for this radio. But from what I've seen on the other 3600 chassis and schematics, then TR32 should be the AM Limiter. This chassis has been around for awhile and there have been many variations on this theme.

TR53 for AMC, TR32 for mic amp/alc I think but don't quote me lol, these two are the usual suspects.
r249 maybe clipped to disable AMC also

 

[Robb]

TR53 for AMC, TR32 for mic amp/alc I think but don't quote me lol, these two are the usual suspects.

Think its the other way round . . .

 

[LeapFrog]

Think its the other way round . . .

Could be, I would have to go look at one of the Galaxy boards/schematics but these often got clipped/pulled by screwdrivers.

#6-Galaxy Rigs (models with the EPT360014B boards)>>To boost A.M. modulation,do NOT cut or remove TR-32!!!This can adversely affect SSB,causing overmodulation and severe splatter!!!!The proper way to boost A.M.,is cut one end of R249,and remove TR53 from the board..this will really boost the A.M.,but has NO affect on SSB..

Taken from this pdf.

 

[Robb]

Oh yeah; also check C189. Way in the back/right side of the radio. See if there is a resistor/diode where Ci189 should be.
http://www.angelfire.com/electronic/cbdoctor/npcrc360014b.html

 

[2FB327]

Thanks, I'm going to get after it now.