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Post by BBB on Nov 8, 2015 11:01:21 GMT -5
There's nothing "Ultra" about this Walmart 3 knob CB radio, but I ran one last night for fun and had some folks saying it sounded good with a power desk mic. The PC board is labeled 19DX-IV and DM1 is lifted. I kept an eye on the modulation level and kept harmonics to a minimum. It was actually pretty clean on the analyzer. Ultra-Cheapo Radio...  |
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Sandbagger
Administrator/The Boss 
Posts: 6,247 
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Post by Sandbagger on Nov 8, 2015 11:34:55 GMT -5
There's nothing "Ultra" about this Walmart 3 knob CB radio, but I ran one last night for fun and had some folks saying it sounded good with a power desk mic. The PC board is labeled 19DX-IV and DM1 is lifted. I kept an eye on the modulation level and kept harmonics to a minimum. It was actually pretty clean on the analyzer. Ultra-Cheapo Radio... Interesting, I was just at Walmart yesterday, and happened to see one of those. Two things struck me. One, the size of the box that it came in (super small), and the second was the price. $38 for a CB radio. I couldn't even get a 1 Watt walkie-talkie for that back in the 70's....... So what does DM1 do? Modulation limiter? |
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Post by BBB on Nov 8, 2015 14:24:48 GMT -5
Yes, previous owner induced. Since I have it on the bench, I'll reconnect it and see how it does.
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Nov 8, 2015 16:16:36 GMT -5
Yes, previous owner induced. Since I have it on the bench, I'll reconnect it and see how it does. The problem with radios, which do not have adjustable AMC circuits, is that often with the limiter in the modulation is too low (70-85%), and with it out, it splatters with overmodulation. What I usually end up doing in those cases, is changing the value of the fixed resistors in the limiter feedback line, until I can get a nice regulated 100%. It usually takes a little trial and error, but not too tough. |
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