Hello guys i need help identifying these board's below
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Need help identifying these boards
- Thread starter kaos513
- Start date
The one with two crystals looks like an "uppers/lowers" mod kit.
The red epoxy thing is likely a noise toy wired to the push button, what's next to it looks like a roger beep (maybe an echo but I doubt that).
That's what I see, hope it helps.
The red epoxy thing is likely a noise toy wired to the push button, what's next to it looks like a roger beep (maybe an echo but I doubt that).
That's what I see, hope it helps.
Expo 100, originally through CB City International.
the AM Mix is .91 + 10.240 (divided by 1024 for the channel spacing) divided by two for 5.12 x 3 for 15.360 plus the TX oscillator 10.695
the .455 is derived by subtracting 10.240 from 10.695
so ...
.91 (channel one) + 15.360 + 10.695 = 26.965
the crystals will be .44 + 1.35 upper
and .91 - .44 lower
The signal from a simple Pierce oscillator is injected into the mix over powering the 15.360Mhz signal generated in the PLL .
Its not the best practice but it works .
The other ? Noise toy .
If I'm not on the ball or I missed the math, get in here and correct it please
the AM Mix is .91 + 10.240 (divided by 1024 for the channel spacing) divided by two for 5.12 x 3 for 15.360 plus the TX oscillator 10.695
the .455 is derived by subtracting 10.240 from 10.695
so ...
.91 (channel one) + 15.360 + 10.695 = 26.965
the crystals will be .44 + 1.35 upper
and .91 - .44 lower
The signal from a simple Pierce oscillator is injected into the mix over powering the 15.360Mhz signal generated in the PLL .
Its not the best practice but it works .
The other ? Noise toy .
If I'm not on the ball or I missed the math, get in here and correct it please
Cant find any info on the expo 100 kit,closest i came to was cb tricks but does not match this board thanks.
Find out what the markings are on the channel board xtal, as this will help determine what radios they were designed for.
The board with a blue relay on it is a noise toy; probably a roger beep.
The board with a blue relay on it is a noise toy; probably a roger beep.
Read the crystal markings frequency like 14.910 etc.
Follow the links
http://www.cbtricks.com/miscellaneous/vco/expo/model_a.htm
http://www.cbtricks.com/members/cblincoln43/A + kit ANL Sw 3bmp.gif
Follow the links
http://www.cbtricks.com/miscellaneous/vco/expo/model_a.htm
http://www.cbtricks.com/members/cblincoln43/A + kit ANL Sw 3bmp.gif
I believe you, I have the same board here, no xtal markings stamped!
The only way to be certain is to test each crystal and record the frequency.
http://www.electronicdesign.com/test-measurement/simple-tester-provides-readout-crystal-frequency
Edit: or make it oscillate and check the output with a counter
A better clue might be if you know what radio that board came out of..
I believe they made many different versions of that expander board.
Best Regards
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Should be the equivalent of the Expo 100 "A" kit.
Red is 12-Volt positive, black is negative, orange is output to the PLL's 15.36 MHz downmixer input.
We got in the habit of hooking these up to a small bench supply, with the frequency counter on the output wire. If a kit won't set on frequency properly, the best time to find out is before it's installed in the radio.
To go down 45 channels, the lower side should set to 14.910 MHz. Upper side to 15.810.
Some older Expo kits took you up and down only 44 channels, not 45.
Might be a clone?
73
Red is 12-Volt positive, black is negative, orange is output to the PLL's 15.36 MHz downmixer input.
We got in the habit of hooking these up to a small bench supply, with the frequency counter on the output wire. If a kit won't set on frequency properly, the best time to find out is before it's installed in the radio.
To go down 45 channels, the lower side should set to 14.910 MHz. Upper side to 15.810.
Some older Expo kits took you up and down only 44 channels, not 45.
Might be a clone?
73
You need to find out the crystals value like Nomad explained using his technique which is the easiest way to do it
Or if you want to build your own crystal tester
http://www.cbtricks.com/members/rick_euro_radio/erc_crystal_tester.pdf
but you still need a frequency counter to find out the value
Some crystal have the value printed on the side or stamped on the top
Or if you want to build your own crystal tester
http://www.cbtricks.com/members/rick_euro_radio/erc_crystal_tester.pdf
but you still need a frequency counter to find out the value
Some crystal have the value printed on the side or stamped on the top
And that's not all. The instructions for the Expo 100 type "A" don't work terribly well. The instructions from 30 years ago were different, and that hookup works fine. But somewhere along the line they changed the procedure, and the new method is not as reliable.
We use a "bench" type frequency counter with the input probe on the orange wire, grounded to the black wire, with the power supply feeding the red wire.
That, and I tend to also check it on a 'scope to make sure it's putting out at least a couple of Volts P-P of RF.
Expo kits for the Cobra 29 tended to have one crystal marked "J", and the other one marked "T".
73
We use a "bench" type frequency counter with the input probe on the orange wire, grounded to the black wire, with the power supply feeding the red wire.
That, and I tend to also check it on a 'scope to make sure it's putting out at least a couple of Volts P-P of RF.
Expo kits for the Cobra 29 tended to have one crystal marked "J", and the other one marked "T".
73