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Receive transistor in amp - same/same?

It appears to be M604 to me. Here is as close as I could get to it and still get a decent pic.
 

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No worries man! If I can help I surely will. You gents ha e certainly helped me several times! Just trying to pay back a little of the help I have gotten from the forum and members such as yourself! Hope it helped.
73 and God Bless
Sean.
 
Used the
10w drive should make about 200w output with a pair of 454's on 13.8v,

i have come across amps that have high vswr and attenuate your power in bypass mode, cp163's do it,
sometimes a trimmer cap from the bypass side of the relay to ground will tune out most of the mismatch.
Used the mfj259 antenna analyzer on the amps input. Read that the SWR is 2.6:1.
So, it is in need of tuning.

Problem is, I don't have any variable compression caps - or any other variable caps - to determine what value is needed to bring the input SWR back into proper working order.

Put a 2N2222 in the receive amp, and it works again. Bought it at Radio Shack with some 2N3904's in a 15 piece variety pack for $3.50. So, one problem down and one to go.

Keep you posted . . . thanks!
 
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Keep at it Robb. Sounds like you are on the right track and will have it resolved! Job well done man!(y)(y)
 
robb,
have you looked for burnt parts that could be causing the bypass missmatch? sometimes amps have a cap,

not sure if you can get at the relay bypass to tack small caps on in that amp without major messing, its worth a try if you can and you cant see anything else connected to the line that could be damaged,
 
robb,
have you looked for burnt parts that could be causing the bypass missmatch? sometimes amps have a cap,

not sure if you can get at the relay bypass to tack small caps on in that amp without major messing, its worth a try if you can and you cant see anything else connected to the line that could be damaged,
Have the board out again and testing parts for failure. No luck so far. Not giving up - tho. This would be easier if I had a schematic for it; but cannot find one on the net anywhere.

The input coupling cap is OK and other resistors/caps too. Tested every diode and transistor on the board - except for the keying transistor because I know it works. The relay is still a suspect, since I have not found any other part failed as yet. But if it does have problems; is this a standard relay that can be replaced easily?

Something is obviously not allowing the main transistors to reach full saturation. Draws only 12-15A under a full load in SSB mode; about ~130w output/max. 100w/max in AM mode.
 
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You know I don't know shizz about radios and amps Exit13! I will be the first to say that! All I can do is look at a board and see similarities and try to help by taking pics! I hope it helped Robb a bit. If I wasn't so gun shy abohtselling stuff, I would have already sold off most of my radio stuff that isn't beinf used. But since I am the way I am. I worry to much that the amp would get to someone and not be working.
Also I comnemd Robb for trying and also fixing the amp as much as he has with out a schematic as well!! Again, like I said, job well done man!
Wish I had the money as I would send you a couple of radios and also an amp i have that needs work Exit 13. Times are just tough! Maybe some trading of items for work might be a way i could get some stuff done? Bout the only way I am going to be able to have any work done these days!!! Anyhow, just wanted to say great job to Robb and also hello and hope all is well with you my friend. Bracing for the hurricane here! Going to get nasty! Hope my antenna makes it. If I get home today and it's not pouring rain I may try to lower it!! For now it's guy roped off big time!! Use ratchet straps as well as para cord and Dacron rope at about 4-5ft from the base of the antenna. Let's hope that will do it! My fingers are crossed. This storm could do some serious damage just the way it's tracking now and God willing it won't mine any further west as we will get hit even harder! People here aren't taking this serious!! They are going to be surprised as shizz when this thing gets close as it's not a little storm. Anyways, to all have a good day.
 
Awesome man!! Glad you got it resolved!! And hopefully some of the pics helped. I think.m Exit13 knew best what the part was!! I darn sure aren't any type of amp tech LOL!! Anyhow, again great job!! Have a good one Robb!
73 and God Bless
Sean
 
Used the

Used the mfj259 antenna analyzer on the amps input. Read that the SWR is 2.6:1.
So, it is in need of tuning.

Problem is, I don't have any variable compression caps - or any other variable caps - to determine what value is needed to bring the input SWR back into proper working order.

Put a 2N2222 in the receive amp, and it works again. Bought it at Radio Shack with some 2N3904's in a 15 piece variety pack for $3.50. So, one problem down and one to go.

Keep you posted . . . thanks!
I thought I read somewhere to use the analizer on an amp input but could not find it again. Is this procedure as easy as it sounds? Thanks!
 
I thought I read somewhere to use the analizer on an amp input but could not find it again. Is this procedure as easy as it sounds? Thanks!
Mind you, I'm no electrical engineer nor do I have a vast electronic background or knowledge base. I'd read someone using the analyzer to measure the capacitive and inductive reactance through the unenergized port. Although the output combiner and cap are doing something completely different than matching, I think it would be better explained by someone else that can give it the details your question deserves.
 
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