Total noob trying to ID mods of previou owner

[phurst]

Greetings! Glad to find what looks to be an active and helpful forum! I've been thinking about getting a CB/SSB base station off and on for a few years now, to set up in my workshop just for something to mess with while I'm in there working. As luck would have it, a Cobra 142 GTL popped up near me. I understand this is (or can be) a decent unit, and the price was more than reasonable, so I ended up picking it up today. The ad said the clarifier unlock mod had been done, and after a bit of research, I figured out what that meant . If it's not obvious already, I'm a COMPLETE beginner here, not having used anything even resembling a 2 way radio since I was a kid playing Walkie-Talkies with my friends. Anyway, I got the radio today, and it obviously has at least 2 other mods, as there are non-stock dials on the back of the unit. I have included a couple of pictures for reference. The one higher up on the case is a dial with detents, meaning it has definite positions, like the channel dial. The lower one is a smooth sweep, with no detents, like a volume knob. I recognize that you guys might not be able to answer, since you can't see where any of the wires go, but I didn't know if there were common mods done on these units, and y'all might be like "oh yeah, that top one is clearly a cloaking device, and that bottom one tunes the flux capacitor, duh!". I can certainly further disassemble if necessary. And yeah, the obvious solution might be "hook it up and see what they do", but one, my antenna hasn't arrived yet, and 2, I'm so freaking new, I honestly wouldn't be able to reliably tell what any giver switch or dial does unless it's in the manual. I don't really know yet how it's SUPPOSED to work, so I wouldn't know if either of these were changing anything . Anyway, if anyone has any ideas or suggestions, I'd be interested in hearing them, and please try to explain them to me like I'm a 9 year old .

Pictures!

https://imgur.com/a/bpj4Bef

 

[jassing]

Welcome to the forum...
I know this isn't what you asked -- but for a brand new person, I think it's best to start with an unadulterated radio.
Clarifier unlocking isn't always that helpful; personally I've not had it done on any of my stock or custom radios.
Your money is best spent on a good antenna & coax rather than a modified radio. It doesn't look like a professional job on the radio, so I wouldn't expect it to perform well, especially for such an old radio. (Often the older radios need electrolytic capacitors changed, as they dry up).

My guess is that the upper knob might be a variable power. An approximate rule of thumb is that you need to double the power to get any noticeable improvements. so 1 watt vs 2watts is noticeable, 2 watts vs 4 watts, etc. but 4 watts vs 5 is negligible, all you're doing is wearing the radio out.
The lower knob might be something to get 'between' channels, but it's just a guess. This sort of mod is worthless, unless you know someone else is also doing it, or has a misaligned radio and you want to compensate for it. You'd want to get a frequency counter (if that's what it is) so you know where you are when you're transmitting.

Those are just guesses. Good you're looking at SSB radios; it's mostly a lonely thing, with some just transmitting to hear themselves talk, but eventually you'll meet others and they'll learn what channel you camp out on and where they hang out.

 

[2IR473]

Generally, modifications to CB radios are done to provide additional channels beyond the 40 channels of the CB radio service. This would typically be accomplished by adding the additional knobs and dials like your radio has. Also, as mentioned, adding a dial to adjust the power output is usually added so an amplifier can be used with the radio, to increase the transmitted power, as you would want to turn the output of the radio down, to drive into the amplifier.

The clarifier modification is done to allow the radio to “slide” between the channels...ex. channel 38 is 27.385 mHz, but you will find people transmitting on 27.380. The clarifier modification will allow the radio to tune AND transmit there. Many people do these modifications, but their real value is subject to question as to whether they are really worth doing. Mostly, they screw up an otherwise fine radio.

Since you say you are a complete beginner to all of this, I would urge you to exercise caution with this radio, as you probably won’t know where you are transmitting, as the Cobra 142 will only display a channel number, but this is not an accurate display of where you are, on a modified CB radio. Channel 1 could be a number different frequencies, depending on the modification and position of a switch. Understand that while it is done, transmitting outside of the 40 channels is illegal. And for someone that is not familiar with this type of activity, this is not the type of radio I would suggest for a noob.

Also, these modifications are often done to rather poor standards, and that can result in the radio being off frequency particularly noticeable on SSB. This can be very frustrating to someone not familiar with SSB operations, and cause them to give up, without realizing the radio is improperly aligned.

However, the 142 is generally a very good radio, and if that radio were restored to it’s out-of-box condition, along with a proper alignment, it would be worth keeping, but I would have suggested something like a Uniden 980 SSB or President McKinley for a first sideband-capable radio.

 

[2IR473]

BTW, If you are looking for an active forum that is specific to CB and ham radio, here is a link to a forum that has been around since the late 1990s. It has changed names since it first started, but has remained active with lots of good information about CB (and also ham) radio. I have been on this forum since it started, as it grew out of the old newsgroups that existed back in the day (this came from the alt.rec.cb newsgroup...who remembers that !).
WorldWideDX forum

 

[phurst]

Thank you guys for the advice (and the link). I've already got it, so I guess I'll give it a shot, and if I'm having difficulty or frustration, I'll certainly consider something that is 100% stock.