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My old friend President Jackson.

all i had at home was my old ratshack meter that would measure ma,, and if i remember using it last time it was a p.o.s.,, ill take a measurement at lunchtime with my fluke meter here at work.

im probly just in over my head on this radio, im a mechanic and DIY'er for about everything, but never messed with radio internals till about 6 months ago when i got back into it. i can do most stuff if i can see a vid or read up and do some research, but i dont have any of the equipment needed for this type of advanced radio alignment/set-up procedures.

im 100% happy with my base set-up, and if this radio doesnt work out i cant see spending big$$ on a $150 radio,, so i may just try another thats set-up better out of the box for mobile use. but im not giving up just yet,,lol the radio does receive great thats for sure!

and a big thanks to people like Robb and m42duster for helping with mods and advice on the radios!!


bias measured: ratshack meter

-vr10 tp8,tp6 115ma
-vr9 tp8-tp7 2ma

set vr10 to 50ma, vr9 maxed out at 40ma??

re-tested with fluke meter and values are about the same, give to take a few ma.

also TR26 is still in this radio as it was an un-opened box from copper. and vr12 does nothing at all.
 
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I can't say it is a bad radio yet. I have talked a bit on SSB today and everything seems Good. I will have to work on getting VR12 to adjust and I am sure I will then get more than 13W on AM. So far it is Good on Sideband. In the next day or two I will do a complete alignment and go from there.
 
Low_Boy said:
I can't say it is a bad radio yet. I have talked a bit on SSB today and everything seems Good. I will have to work on getting VR12 to adjust and I am sure I will then get more than 13W on AM. So far it is Good on Sideband. In the next day or two I will do a complete alignment and go from there.
Click to expand...

Spec sheet/owners manual says 10w on AM/FM. It is a 40w output device. I'd be real careful not to pop a rare and expensive device like this one is.
 
I agree, however it is only a low beta device. While it would suck having to buy one I would feel better with the normal high beta devices that were used in most radios back then.
 
bob85 said:
yes the jacko is popular over here, much more common than the grant,
they both have their pros and cons.


rob,
check the resistors in the bias circuit are the same value as the jacko, check for leaky caps, check or replace the mv1y, if all checks out ok and the voltage source is at the right voltage i would suspect the final has a much lower beta than the original 477,

i have used lower beta motorola green dot 477's in jacksons with good results, they bias ok and still give more output than is healthy for the rest of the pa stage.
Click to expand...

Those parts all check out , Bob.

So what you are saying is that this particular MRF477 that we are seeing in this radio will need to be biased much lower than the original Jacko requires? And if so; then what should I set it at? Should I also change the biasing on the driver to accommodate it as well? If so; then how should it be set? Just don't want to burn up a rare final as this!

When I got this radio, the driver bias was set at 266mA and the final bias was set at 0mA. I now have the driver set at 50mA and the final at 35mA - which is maxxed out. The final doesn't get beyond skin temps when talking on SSB for two minutes and getting 40w output on a peak reading meter.

The other problem we are seeing here is that VR12/AMC control does not seem to be working. Is there one particular part that is pulled to modify AM modulation that would cause this issue? TR26 was yanked off the board and I already replaced it. Any other part that someone might have clipped out?

Trying to understand this beta concept here bob85, so please bear with me a minute. You know these boards real well. Still relatively new to fixing radios, so anything you can tell us would be much appreciated.
Thanks again!
 
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Any updates on these radios?I just now finished the frequency expansion on
mine Unsoldering the solder bridge.I noticed that there was a resistor on the pin side of the board with one leg unsoldered,is it supposed to be that way.I bought the radio from copper so im pretty sure that nobody has been in the radio but me.Also what other mods would yall recommend doing to this radio.I was thinking about doing the clairifier mod and agc mod with the help of a local tech.
 
red97k1500 said:
Any updates on these radios?I just now finished the frequency expansion on
mine Unsoldering the solder bridge.I noticed that there was a resistor on the pin side of the board with one leg unsoldered,is it supposed to be that way.I bought the radio from copper so im pretty sure that nobody has been in the radio but me.Also what other mods would yall recommend doing to this radio.I was thinking about doing the clairifier mod and agc mod with the help of a local tech.
Click to expand...

post up a pic.
 
I guess the factory rep is on holiday until this Monday. Supposedly, this is when Ranger is going to see if this radio is going to be under a factory warranty.

Any guesses as to whether they'll claim this one?
 
mine is working fine now, had a couple bugs pop up but audio sounds great, made a bunch of contacts today and made several recordings from home to test the audio. also installed a frequency counter. Its up for sale locally here, i think id like to try out the m-8800 for the mobile.
 

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camaro1 said:
mine is working fine now, had a couple bugs pop up but audio sounds great, made a bunch of contacts today and made several recordings from home to test the audio. also installed a frequency counter. Its up for sale locally here, i think id like to try out the m-8800 for the mobile.
Click to expand...


would you post a picture of how you hooked up the freq counter? also is it on line with ssb as it is on AM.
a lot of people would like to see that for sure.
thanks
 
sonoma said:
would you post a picture of how you hooked up the freq counter? also is it on line with ssb as it is on AM.
a lot of people would like to see that for sure.
thanks
Click to expand...

yes am/lsb/usb all in line

it is very easy install,

-the center of the freq lead goes to a 39pf cap then to R73, the shield gets soldered to a can
-brown is ground and also soldered to a can
-red goes to a 8v source, easy to find on the main board or the switch board
-yellow goes to a 10k resistor then to the orange wire at the mode switch(+8v in lsb mode)
-orange goes to a 10k resistor then to the red wire at the mode switch(+8v in usb mode)

the lsb and usb wires go from the mode switch to a plug in connector at the main board and are plenty long to tap into for connection

just do a search on youtube, there is a vid of install on an original jackson, but he pulled the switch out to tap into the usb/lsb wires, you dont have to do this there is easier ways


I actually had a good time using the radio today, i was in the suv for a bunch of short trips today and made contacts every trip, the frequency counter is nice to have especially in a cold vehicle to get lined up right away without having to listen for someone else talking.
 

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