Sunday, October 23, 2005

ONLY ONE MOD
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When you buy a CB, in particular, a SSB CB, what "mods" should you do?
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The question should be:
"What MOD should you do?"
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IMHO (And Uncle Charlie, don't leave me off your X-mas list this year for it), the only mod you should do is the clarifier mod**.
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A single-sideband radio without the ability to minutely track tx/rx together is only good if you're talking to one other person. But when more than two people are in a conversation it's a real pain to have to move the clarifier for each one - thus the clarifier mod: "everyone is on the same page".
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Adjusting a radio from 3 watts to 4 watts will not do a thing on the other end.
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Clipping the modulation circuit will make you "King of the airwaves" (briefly). It will also make many enemies, because in truth, you will be the "King of splatter".
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Adjusting the modulation? Well, they're pretty well adjusted from the factory. Usually the biggest issue with modulation is not how loud it is, but the quality (too muffled, too tinny, too much bass, etc.). This is where you buy another microphone. I know I've told this story many times before, but I purchased a Uniden PC-122XL about 10 years ago as a backup rig. One day I needed this to fill in for my usual rig, so I threw it on the passenger side seat, plugged it into the cig lighter and off I went. Because it was a backup rig I didn't want to spend any extra $$$ for an after market microphone so it had the original mike with it. Later that day I ran across my radio 'bud "Doug" (currently semi-retired from radio operation) and he wanted to know what I was talking on. When I told him a "stock" PC-122, he came back with:
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"You've never sounded more natural"
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(Guess I didn't need any "MOD's", eh?)
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I know, you're wondering about extra channels. I categorize this mod as "Borderline", and leave it up to you. Usually, when there is any activity going on, you'll find the brunt of it on channel 38, thus no freq. mod's required.
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If you were paying attention, you noticed two ** after the clarifier mod. I did this because some rigs will sound like crap after it's done and would sound much better by having a shop put the rig center-slot rather than do the mod. If you've been talking SSB you know what I mean - those rigs that tend to have modulation with a warble, or flutter that makes them hard to understand. Usually, these are rigs made in China, and usually it's due to crappy/cheap components.....
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'Nuff Said

2 comments:

  1. I agree 100 percent!

    Man, those PC 122s were good radios. They are a real pain to try to get an expo kit to work in, though! (Of course for transverter use, only...)Too bad Uniden doesn't make any SSB gear any more.

    You know, I've found that using a Heil HC-5 microphone element in a stock microphone case will help just about any CB sound really great. (No, I'm not associated with Heil. I just like the mic elements.)

    I have an old President Grant Classic that I run in the shack most of the time. I have never turned up the ALC, AMC, or anything. I just added a Heil element, and folks tell me it is the best sounding radio they have ever heard - even on AM! Can't beat that!

    The only other mod that I usually do other than frequency and clarifier mods is to add a variable carrier control to a radio.

    For example, I have a Superstar 3900 that I re-crystaled up to 10 meters. I run AM on 29.050 Mc with it, and need a variable carrier control so that I can properly drive my solid state amplifier.

    So, what I did was to disconnect the SWR calibrate pot, unsolder the carrier adjust variable resistor on the circuit board, and then wire the SWR pot up to carrier control point on the board, itself.

    I made notation in my files on how to change things back stock if I ever wanted to. For now, though, having that carrier control is much more valuable than having SWR measuring capabilities. Heck, that job is handled by my main watt/swr meter, anyway.

    Now I have added electronic keying capacity to a number of CBs, also. I usually unsolder the wires (or cut the traces) going to the PA jack. Then I hook a little homemade circuit between a point that goes from 8-12 Vdc when the radio is keyed, and the PA jack.

    This device allows me to hook up a control cable to a standard "ham" amplifer, and control it electronically via my modified PA jack. No foot pedals for me - That is, when I key the radio, the amplifier keys, and when I let off the key the amp also unkeys. This is very handy for easy SSB operation.

    Just my 2 cents...

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  2. Hi Woody!

    I finally gave in to the urge, and bought a new Uniden Pc 78XL for a really great price. Unfortunately, it is made in China...

    However, it works as well as my old PC 76, and the parts look first rate. Maybe Uniden has figured out a way to make those Chinese produce decent radios after all!

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