Hello guys, so I heard a rr com comp 29. It’s was LOUD , I mean walking the dog loud. Must been driving a amp nobody talked over this 29. That being said I always wondered why the 29s and uniden were choice for key downs? Because they don’t back down ?? Thanks
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Comp cobra 29
- Thread starter Ziploc
- Start date
Never heard one myself. The special tune jobs and secret radio tunes are interesting discussion. The website you are mentioning is R&R Communications in Delaware. I believe it is called Dustin's Competition Cobra. It refers to making the Dust Mod in the the radio which is a forward swing mod. I am not to judge, 1. I have never heard one on the air. 2. I am not a radio tech. If you like how it sounds put one in your future. I have a collection of a few radios from different techs myself. Have a look through R&R Communications website. Be sure to look at Dustin's message discussing CB radio shop black lists. It's a interesting read. At the time of creation I do believe that R&R was trying to create a name brand mod. It never made a splash as some others.
I know a little about these competition 29's. 631 was saying once in another forum that he and others found a short run, 6-8 months or so of cobra 29's from the early 1990's that they say tune differently. Something about certain parts or combination of parts that were used for a relatively short period that makes them different. These radios from what i understand are mainly used for key down comeptitions hence the comp designation. They arent really meant for broadcasting. I bet he was splattering bad, several channels either direction at the very least. Very loud but very dirty. Ill have to look at my old pms from that forum as i seem to remember he may have dropped that info there if not ill ask him what the years/months to look for.
Comp 29s are a gimmick. I've had a Dustin 29 and he did a wonderful job on the RX tune. All that extra power made the output transformers in my amps talk and I gained no power out of the amps. Why? I had enough driver to push the final amp well into saturation. All the comp 29 did was make the ferrite rattle at an audio rate and bleed on my stereo.
A 29 from the right era is a beast with a tip 120 or whatever flavor transistor you like mod. Pull a turn off of L14 if it's a modern rig. Jump D8 if you want and be done. You can dick with the audio section and get some more crunchy out of the audio but it's not worth it.
A 29 from the right era is a beast with a tip 120 or whatever flavor transistor you like mod. Pull a turn off of L14 if it's a modern rig. Jump D8 if you want and be done. You can dick with the audio section and get some more crunchy out of the audio but it's not worth it.
Like 543 said certain eras produced some radios that could handle certain mods better than others i guess. From what i see you would need to modify a ton of 29's to know what radios from what eras did the trick. I messaged 631 to see if he remembers those production dates and ill share them if i get them.
They are popular because they look impressive on the watt meter and people don't know any better. Not all of the keydown folk use them but advertising would lead you to believe otherwise.
There is no point in doing all of that work to the radio. If you use a driver that has more gain and headroom it's not necessary. If all those mods produce more harmonics your expensive amplifiers have to take additional abuse.
The reason I mentioned the output transformers in my amps talking is that happens when the output is way out of tune. The only thing I changed was radios. That and the fact it bleeds on the stereo where my other 29 didn't is a red flag.
I already had a big enough driver and was getting all I could out of the system with my mostly stock 29. There was nothing gained from the comp 29 but rf problems. Even when I turned the mic gain back on the comp 29 I still had issues.
The mosfets and crazy mods are not worth doing. I have a couple of old "Davemade Tuned" 29s here. They don't have a lot of BS done to them.
Because keydowns don't use spectrum analysers so it doesn't matter that most of the power being transmitted isn't actually on the channel the rig is set to. I've you've got a rig that's quite happy to spunk out harmonics over several dozen kHz you can get the amp it's driving to do just the same which may make the watt meter swing just a little further.
It would really make keydown contest results interesting if the rules only measured power transmitted on the channel you're tuned to. I suspect that the power readings would be way lower.
So Mr. 631NJ got back to me. The 2005 cobra 29's have a different audio ic that allows for more pep.
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Sorry but that's crap. There may be a higher average wattage on SSB/AM but there won't be a higher peak wattage. Anyone who thinks that there is is clearly not using the right kind of power meter to measure PEP. If the power meter claims to be able to read PEP without requiring a power supply then it's not a proper true PEP meter as the proper meters for the job use a powered circuit containing op amps.
Higher average power is what the comp guys want. With the peaks flat topping all the way. The area under the curve is what they are trying to maximize. They might as well be running in FM. This is part of the debate around high dead key too.
The cobra 29 is a high level modulated AM only rig. Class C final and a modulation transformer. No ssb. Some of them do make more pep than others without extensive modifications.
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