| Author |
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123upmichigan
| | Posted on Wednesday, January 01, 2003 - 12:50 pm: | 
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hello i am working on a uniden president grant export and i was wondering if it was possible to get a 5 khz down slide on the clarifier.. any help would be appreciated thanks 123 up michigan |
2600
| | Posted on Wednesday, January 01, 2003 - 5:17 pm: |
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There has been more than one radio sold with this name on the outside of it. If you can tell us the circuit-board number, this would narrow you down to just ONE radio. The nitty-gritty stuff to increase the voltage swing FROM the clarifier knob is specific to the circuit board your radio has in it. On some radios, this is all it takes, along with setting the adjustments inside that line up AM,LSB and USB frequencies to match each other. So far as I know, none of them requires any extreme measures, like adding a choke to the crystal.
73 |
123upmichigan
| | Posted on Saturday, January 04, 2003 - 7:49 pm: |
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allright the board number is pc-999ac. hope this helps |
2600
| | Posted on Monday, January 06, 2003 - 1:42 am: |
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I hope I'm not screwing around with somebody's copyright stuff here, but information from the "Uniden Export Service Manual" sez:
Lift the Gray and Blue clarifier wires from where they enter the main PC board. Connect the Blue to the unused hole at the right of the empty "R120" location. (Front edge of the board, next to the coils and crystals.) Install a 470 ohm 1/4 watt resistor at "R120". Connect the Gray wire to a constant DC voltage source. There are 2 unused circuit holes in the PC trace leading to the Collector (center lead) of TR39 Voltage Regulator, bolted to the side of the chassis.
Remove D45.
This should do the job without having to add choke coils to the varactor diodes D40 and D44.
You may need to set the center channel frequency with the knob pointer at 3 o'clock instead of 12 o'clock. With the coils L22 through L27 set for the channel center at 12 o'clock, it may or may not slide enough to suit you. With L22-L27 set for 3 o'clock, it should still slide up about 1.5 kHz and down at least 5 kHz, usually more like 12.
73
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