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I removed R143 and replaced it with a 5.1k ohm. I now have slide from 27.2012 at the lowest position up to 27.2088 on the highest position. That's 3.8k of slide on both sides, and the clarifier is still centered at 12 o'clock for being on frequency. I tried shorting out R143 with a jumper. The...

I noticed on the 2000/148 chassis, the R174 which is directly tied to the center (wiper) lead of the clarifier. Which most people place a jumper across. Well the first resistor tied in with the center (wiper) lead of the 142 clarifier is R143, which is a 10k. So, should I replace the R143 10k...

Hmmm, after thinking over it a few minutes, R415 isn't even in the clarifier circuit any more since I removed the red/white stripped wire from that location that's tied in with R415. The red/white wire is now on the main PC board ground track. How can I get more range without that choke, with...

I compared the schematics of the 2000 and the 142 against each other and came up with R415, which is on the switch board and tied into where the red/white stripped wire came from factory. Someone has a jumper across this resistor. I should remove this jumper and try something like a 2k right...

Got a Cobra 142 GTL base on the desk today. Issue(s): 1. Squeals through speaker when Transmitting. 2. Clarifier not centered at 12 o'clock. 3. Receive weak in all modes. 4. Both sidebands sound terrible. Evaluation: 1. The external speaker jack on the back of the radio is loose, which...

I use this variable key method on all cobra 29, 25, etc...and it works great. The only change I make, is to replace the 100 ohm resistor coming from the lowest tab of the external potentiometer to ground with a 1k ohm variable resistor. In place of the 100 ohm resistor, solder the wiper tab of...

I set the driver bias to 4.25v and both the finals to 3.80v each. Reset carrier levels for RF power all the way up to a 9w key and all the way down to a 1w key. Replaced the modulation VR inside the radio due to other one fluctuating badly when adjusting. Added a 22k ohm resistor across the...

Was gonna set the bias, can't check it in ma mode due to AM only, so had to try the voltage route. When I hooked volt meter to test point for driver bias, it was set around 4.6v, the finals were set around 4.4v to 4.8v. Anytime I had to go the voltage route for MOSFETS, I've set them for 3.80v...

Those 73v's were produced for only 2 years. I've gone through one for a friend, he won't part with it no matter what people offer him. Not many 73v's around anymore, if it works then hang on to it.

That fixed it, although I think the 2076 just wasn't making a good connection. Output: Variable power wide open yields a 9w deadkey, swings to 40w PEP, 20w average. Variable power all way down yields a 1w deadkey, swings the same as above, hmmm, swing mod somewhere in it. Anyway, it's fixed of...

According to Alltransistors database, the 2076 will sub for a 945. Regardless, I'm putting in a 945.

Got a Mirage mx-36HP3 on the desk today. Board number EPT-DX2912Z. Issue: Transmit audio has constant oscillation sound, sounds like background air noise and can't be brought down with mic gain off. Evaluation: Q39 looked burnt under it on the board. Removed Q39 and noticed it's the wrong...

I use alltransistors website to lookup subs so I can compare to all these unknown, but in the CB bins from his shop, but I'm unsure of their lists. He has bags and bags of transistors (TO220) that are in the CB section of his shop, I got them all. Some are marked as: BC... K... Kk... C... 2N...

That's all he has in the 2SC2312 bin (several of these). He has everything pretty well organized on all the other bins it seems with the parts and labels matching or being a sub I can locate and confirm, except these. Gonna try one out and see. Anyone have a list of available subs that could be...

I just got done cleaning out the years long tech that recently passed away. He had a lot of new parts. But I have some questions for the experts on this site. One of the parts containers has new finals in the compartment that's marked 2SC2312, but in the container are brand new "en 596N". And...

I don't use any receive mods. A complete alignment is all that's needed to help with receive, most vital adjustments are the VCO voltage, VCO buffer(s), PLL offset oscillators and the carrier offset oscillators. After adjusting those, the receive usually turns out a lot better than before. Pay...

Got another Galaxy DX - 2547 on the desk today. Ehhhh, should I say hacked up 2547, lol. Issues: SSB xmit garbled. RF power control non functional. Extra channel switch broken. Evaluation: Q39 limiter (up front, near mic amp) was gutted out. Wrong limiter to remove on a SSB radio. This would...

I've been getting around 42w to 53w on a lot of these dual final radios lately. But then again, most of those radios looked factory with factory finals and such, whereas this one has been boogered with and by the looks of it abused. I'm assuming the finals are just weak. Everyone says it sounds...

Got an old school Mirage 88 on the desk today. Basically a Galaxy DX-88HL. This used to be the personal radio of a local "tech", ehhh, from years ago. I knew the man personally, and he was good at antenna building and amp building. Well, after looking over this radio, I can't say the same on his...