| Author |
Message |
    
Jameslarson
Junior Member
Username: Jameslarson
Post Number: 39
Registered: 4-2006
| | Posted on Saturday, April 15, 2006 - 1:41 pm: | 
|
Hi. Got a President Madison here. The lights for the meters and clock need to be replaced.
Any idea what the part number is and where to get them?
Also, this radio has a front variably power knob. At it's lowest, the radio swings from 1 watt to 3.5 watts. If I turn the knob all the way up, the radio swings from 3.5 to 4.5. How do I make it swing higher? What VR's or coils need to be "tuned"? Thanks.
PS--Yes, even though the lights are blown, the meters and clock works fine. And yes, it has extra channels. Thanks. |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1162
Registered: 1-2005
| | Posted on Saturday, April 15, 2006 - 2:32 pm: |
|
James, Look to your left. Click on modification list. Find your radio and it will show how to adjust the power .
73 |
Jameslarson
Junior Member
Username: Jameslarson
Post Number: 40
Registered: 4-2006
| | Posted on Saturday, April 15, 2006 - 5:33 pm: |
|
Do I also need to adjust any finals or Bias? Or is it as simply adjusting just the AM power VR and that's it? thanks. |
Jameslarson
Junior Member
Username: Jameslarson
Post Number: 43
Registered: 4-2006
| | Posted on Saturday, April 15, 2006 - 6:11 pm: |
|
O yeah, what about the lights for the meters and clock? Part numbers and where to get them? Thanks
Original President madison (NOT the uniden digital) |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1432
Registered: 9-2004
| | Posted on Saturday, April 15, 2006 - 9:01 pm: |
|
the lamps you want are called "grain of wheat" bulbs.
rad shak used to carry them, but they are probably out of stock.
you can find them at big electronics parts places.
you can also use a white or yellow 12v LED's.
just get a low brightness one, as they can be VERY bright.
biasing the driver and final is very important, its all about the balance of the system. kind of like tuning a carb.
i have the info on how to do it at home. if i can remember, i'll bring it with me tomorrow and tell you how to do it.
you will need a voltmeter that will read milliamps up to 100.
make sure you know how to measure amperage. its not the same as measuring voltage.
this may involve some soldering too. (two wires)
as for the AM power, you are thinking that there is a control inside the radio to turn the power up.
that control is the one that is now on the front panel.
seems strange that it will only key at 3.5 watts max, it wont really matter.
that radio "might" be able to key up at 7 watts if modded, and its going to run really hot.
now here's the kicker: the difference on the listening end between 3.5 and 7 watts is only 1/2 an S-unit.
yep, thats right, 1/2 an s-unit. not really very impressive when you add in the cost of having to replace parts when they go; and they will go.
i do think its a good idea to run a tuned transmitter, so i will find out which coils in the radio you should tune for max while saying "ahhhh" into the mic. (not whistling)
most likely, this is not going to yeild very impressive results, but at least your TX will be tuned for max efficiency. (sort of)
you need to have the right kind of plastic tuning tool to adjust these coils. (not jewelers screwdrivers!) if you dont have the right one, you might crack the slug, and you dont want that.
if you want the radio to "swing" more, and dont care about bleeding on the neighbors TV and phone, (because you will), then you can lift the banded ends of D21 and D22 and add a 4.7K ohm resistor in the vacant holes. this will increase the modulation. i think VR7 is the variable modulation control inside the radio. you can turn this up too.
i think the bulb for the clock is 120vac, but you should trace the wires to be sure.
till tomorrow,
matt |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1444
Registered: 9-2004
| | Posted on Tuesday, April 18, 2006 - 12:27 am: |
|
i havent forgotten about you.
i just keep forgetting to bring the proc. to work with me.
DOH!!!
hopefully, tomorrow will be better,
matt |
|
