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Boxcar
Member
Username: Boxcar
Post Number: 219
Registered: 4-2002
| | Posted on Friday, February 20, 2004 - 4:27 pm: | 
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Well, here's the deal on this radio I got. My tech and I cannot get this radio to swing anymore than 15 watts on am. That's it!! There was another tech that had his hands in here before and did some tinkering around with but we have no clue what to do next. This has the dual 2312 finals in it and it should do more than that. My tech checked the variable on the modulation and that had no effect. The resistor for audio was still in line and we cut it just to see if there was a difference but nothing so we soldered it back in. Only mod's done on this radio that I know of was that npc diode was done to R239 so I'm wondering about that one. That I guess takes the deadkey down and has no effect on the swing. Another mod was clarifier opened up on tx and rx. The warbling was fixed that's common on these for sideband use. As far as that, I am running out of idea's on what to look for. My tech has a lot of knowledge on these boards and we're both stumped. Any idea's people? I would highly appreciate any input because I've posted this in the open forum and got no results!! Thanks!! |
Boxcar
Intermediate Member
Username: Boxcar
Post Number: 223
Registered: 4-2002
| | Posted on Friday, February 20, 2004 - 11:10 pm: |
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any tech's have any idea's?? |
Tech8541
Moderator
Username: Tech8541
Post Number: 87
Registered: 12-2003
| | Posted on Friday, February 20, 2004 - 11:28 pm: |
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what does it do on ssb? |
Cm3885
Member
Username: Cm3885
Post Number: 201
Registered: 12-2003
| | Posted on Friday, February 20, 2004 - 11:57 pm: |
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If i were you if you cant get it to work right id sell it and get a new 2517 or the like.. Nothing worse than a radio that cant swingggggg!! |
Boxcar
Intermediate Member
Username: Boxcar
Post Number: 224
Registered: 4-2002
| | Posted on Saturday, February 21, 2004 - 12:12 am: |
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sideband is fine. doing about 35-40 on swing. am side has got me and my buddy baffled in why it doesn't do much on swing especially when we cut the audio limiter(soldered it back inline though). There is the variable on the am that we adjusted and nothing there either. Aren't these supposed to do anywhere around 30 watts on am?
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Boxcar
Intermediate Member
Username: Boxcar
Post Number: 227
Registered: 4-2002
| | Posted on Saturday, February 21, 2004 - 9:13 am: |
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Which other radio's has the same board in it like the 2980? If i'm told right, is it the 2517, galaxy 88 and 99??? |
Tech808
Moderator
Username: Tech808
Post Number: 1595
Registered: 8-2002
| | Posted on Saturday, February 21, 2004 - 9:44 am: |
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Boxcar,
EPT6900-10Z includes:
Cobra 148F-GTl-DX, Connex 4400, 4800, Galaxy DX2517, Ranger 99, RCI 2960, RCI 2980, RCI 6300, and others.
88 & 99 generally take the EPT3600 boards
Hope this helps.
Lon
Tech808 |
Tech8541
Moderator
Username: Tech8541
Post Number: 89
Registered: 12-2003
| | Posted on Sunday, February 22, 2004 - 10:06 pm: |
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the 2980 has been made with the 3600 board and with the 6900 board. all the newer 2980's use the 6900 board. you said the npc was added to r239 in your radio, so you're 2980 is using the 3600 board like the 88 and 99.
since your ssb is working fine, we know that the tx rf stages are fine or else you would have low output in ssb mode. we also know that the 2sb754 v.reg is fine since the ssb power is fine. the 1st thing i would do is take out the swing mod and put everything back to factory condition. i think you have an am modulation problem, that could very well be caused by a faulty modification. do this and then let us know what you find. |
Cm3885
Intermediate Member
Username: Cm3885
Post Number: 210
Registered: 12-2003
| | Posted on Sunday, February 22, 2004 - 10:16 pm: |
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I did a mod to my 2980 and it seems to work pretty decent now.. Very respectable output.. I found the mod in some of my old notes that i kept for a mod that i did to a Galaxy DX 88 back 5 or 6 years ago.. Good thing i keep everything! |
Boxcar
Intermediate Member
Username: Boxcar
Post Number: 230
Registered: 4-2002
| | Posted on Sunday, February 22, 2004 - 11:03 pm: |
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Actually tech 8541, we're going through and double checking some resistors and variables and making sure they're the stock ones. The board is the EPT360014B one. Thanks for the input. I have been having one heck of a time trying to get any people to help me out. I also appreciate the email Cm3885. I was actually thinking of taking a vacation from this forum because I haven't had much responses at all on this radio.
thanks guys!! |
Tech8541
Moderator
Username: Tech8541
Post Number: 95
Registered: 12-2003
| | Posted on Sunday, February 22, 2004 - 11:59 pm: |
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here are a few other things to do for a quick check of some other circuits that could be causing the problem. tell your tech to ground pin 1 of the balance modulator ic and then try it. also have him disable tr54, the fm mod switch. if it is bad or turned on it will reduce or kill your am modulation. he'll need to do one at a time so he'll know which one if either causes am modulation to work properly. |
Bigbob
Senior Member
Username: Bigbob
Post Number: 1644
Registered: 12-2001
| | Posted on Monday, February 23, 2004 - 5:10 am: |
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Boxcar,I would have posted except the only experience I have with this board is I wrecked the a m tx on my eagle 2000 with my golden screwdriver(fools gold)when I got my 2517 I resolved to never remove the warranty tag on rear and when I am tempted to open it up my eagle is sitting right under it as a constant reminder.Bigbob |
Boxcar
Intermediate Member
Username: Boxcar
Post Number: 231
Registered: 4-2002
| | Posted on Monday, February 23, 2004 - 5:05 pm: |
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Little by little. We're trying to figure this out. It's pretty much a walk through and double checking components and making sure the numbers match. My buddy did find one variable that was supposed to be a 1K ohm variable resistor and there was a 5K ohm in its place and it was the variable for the am modulation. Thanks for all the input guys. Anymore, keep 'em coming! This is a slow and long process of elimination but hopefully there is a light that is shining down on this radio! LOL!!!!! |
Cm3885
Intermediate Member
Username: Cm3885
Post Number: 212
Registered: 12-2003
| | Posted on Tuesday, February 24, 2004 - 12:14 am: |
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Yeah we will get er figured out!!! Ironic that me and you have paralells here with this radio although i have mine pretty much pinned down!!!!! |
Boxcar
Intermediate Member
Username: Boxcar
Post Number: 232
Registered: 4-2002
| | Posted on Tuesday, February 24, 2004 - 6:04 am: |
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I hear ya. I'm kind of running out of idea's though. I know this radio can do more than 15-20 watts. funny thing is I'm having a heck of a time getting much advice on this forum though. Hint Hint!! 
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Boxcar
Intermediate Member
Username: Boxcar
Post Number: 240
Registered: 4-2002
| | Posted on Thursday, March 04, 2004 - 10:23 pm: |
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Wow! Okay, we found a little issue on this radio here. Found an area towards the back corner and it appears something was cooked. TR52, R243, C188 and C193 all appear to have been overheated. Not sure if they're fried but it looks like there are two resistors that were touching that might have shorted out. Going to try and replace these with new ones and see if this am will swing a little more. Oh, did I mention that the variable resistor for the am modulation was changed? Had to change that back also. Maybe we're getting somewhere now................Whew!!!
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