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View Full Version : I got a new radio...Now my amp won't put out like it did before.



T-I-N-Y34
02-01-2019, 04:23 PM
I was running a Uniden 980 for skip with an RM Italy KL 203-P amp. It would push 80-100 watts on am and swing 90-100 on SSB with 2-2.5 deadkey. But now I have A Galaxy DX 2547. With a 2 watt deadkey, it's pushing about 25 on AM and will swing to about 20-25 with a hillbilly whistle on sideband. What's going on? I can talk fine locally but as far as skip I know I won't be able to get out there. Does anybody know what's going on?

sonoma
02-02-2019, 12:34 AM
are you saying that with the amp hooked to the radio you only get about 25 watts out or you saying the radio does 25 on AM without the amp. . if the watts is the radio only that is about right for what the radio is.

T-I-N-Y34
02-02-2019, 05:25 AM
with the radio dead keyed at about 2 watts hooked to the KL203-P amp with the amp on. it's only showing about 25 watts on am. And on sideband, it only swings up to 20-25 watts with a 2-watt dead key. Now when barefoot the radio does 2 watts with the rf power turned down and about 6-7 with it turned up on am.

sonoma
02-02-2019, 05:33 AM
hook the amp back up to the 980 radio and see if it still works. you may have put too much into the amp and fried the pills in it. just verify it still works.
make sure your coax jumper is good also. a loose ground can cause one to not put out as it should. what is the swr also.

T-I-N-Y34
02-02-2019, 05:49 AM
The 980 is toast. It fried. the swrs are all but flatlined. 1.00 or lower. Barely reads on a meter. I can hook the amp up to another am radio to see if it puts out better. I'll get back to ya buddy

T-I-N-Y34
02-02-2019, 06:01 AM
OK, on a 2.5 deadkey it's putting out 60 watts. Only thing I can think is like you said it's a jumper or maybe a ground.. I don't know...lol It's weird. The amp says 5-10 watts input but that's got to be wrong. It'll fry quickly like that right? And I've never put more than 3 in it. I'm at a loss..

T-I-N-Y34
02-02-2019, 06:20 AM
OK, back on the DX 2547 With a 3-watt dead key.(Now that 3 watts is what the internal meter says) (My old PDC1 Astatic says 2 watts) So I'm not sure which one to really trust. The Astatic has done me right in the past. So I'm going with that I think. Seeing as this radio has been opened and may be tuned. So if I am right the internal meter is a little more then a watt off on it's reading. Plus a lot of people I've talked to that run this amp say that2.5-3 is the sweet spot for the amp. Does this sound right Sonoma?

T-I-N-Y34
02-02-2019, 06:39 AM
I set it to a 2-watt deadkey and on am it's putting out about 70-watts. And on SSB it hits about 30-watts with a hillbilly whistle. For a 200-watt amp it sure isn't making much on SSB. Is it possible I did something to the SSB side of things? OH, To get the watts up I took out a switch I had inline and changed the jumper from the radio to the amp. I'm afraid I've messed up my amp. You tell me, buddy...lol

sonoma
02-02-2019, 11:49 AM
have you checked the swr between the radio and amp and then the amp to antenna?
check what your radio is showing power wise with the amp inline and the amp turned off.
you could have a bad relay in the amp. that little amp works best with a dead key just below 2 watts and does not swing much over 10 to 15 watts. your radio will hit that little amp hard even thou it is a single final rig. most 980 radios do not swing much compared to the 2547 you have now.
what makes me wonder about the amp is you said your 980 is fried. they should last for years unless you get bad swr's to the radio. some thing had to blow the 980. they should last for years.

T-I-N-Y34
02-02-2019, 02:04 PM
The 980 was a power fry. To much power got into the radio. It smoked it. It still had received but no transmit. A guy I let use it hooked it up straight when the fuse blew. 14v got in it burn up a strip looking thing in the middle of the radio. And for the SWR. I have the internal meter for before the amp and the Astatic after the amp. They're the same. I can hear the relays opening and closing as I talk. But like you said it could still be one.

JesseJamesDallas
02-02-2019, 09:58 PM
It would take more than just 14v to fry a radio...should be "OK" even up to 16v for a short period...18v would fry it...

As for the other issue with the Amp and the 2547, you may need to find the modulation pot for AM and crank it open some...If this is a new radio out of the box, more than likely the modulation from the factory is going to be somewhere around 75%...adjusting it open would let it swing more. (I had to do this on my President McKinley)...There's probably a SSB pot too that will let you adjust the swing for SSB. ( I also had to adjust the ssb pot on my McKinley to 12w...factory had it set at about 2.5w)

VR 13 should be your SSB ALC to adjust to 11-12w....

I didn't see a pot for adjusting the modulation on the Service manual site from cb tricks, just a pot for the modulation meter adjustment which is not the same thing... There is some adjustments you can do for the high-end side and low end side for AM RF you can do that might help swing, but not sure...

http://www.cbtricks.com/radios/galaxy/dx2547/graphics/DX2547sm.pdf

The KL 203 is not that big a box to start with, I've never had one but from what I've read from those who have them, typically they don't do but around 100w or less to start with...If one of the finals is toast, then that could also be part of the problem...The 203's don't like alot of swing, typically around 10-12w swing...25w swing could have been too much for it.

sonoma
02-02-2019, 11:41 PM
VR13 will control the output of SSB. it is the alc.

T-I-N-Y34
02-03-2019, 06:04 PM
VR13 will control the output of SSB. it is the alc.This is what the guy did.
VR 13.....SSB ALC (modulation) Up all the way
VR 14.....AM high power Turned up to 6 watts. (Can this be turned up more for more output?)
VR 16.....AM modulation up all the way
VR 17.....SSB power up all the way
VR 18.....AM low power at 2 watts.

JesseJamesDallas
02-03-2019, 06:12 PM
I would have VR18 all the way down to 1/2w...still think it's too much radio for a KL 203...too much swing.

sonoma
02-03-2019, 08:56 PM
to me 6 watts dead key for high power is way too much. it is only a single final radio like the 980 you have been using.

T-I-N-Y34
02-03-2019, 11:17 PM
to me 6 watts dead key for high power is way too much. it is only a single final radio like the 980 you have been using.
You know I trust you buddy. I wanna be able to talk locally to the coal truck drivers off the amp. That's why he had the high side up is on 6. And I want to be able to talk skip on the amp. That's why the low side was at 2. The amps just not working the way it was with the 980. The amp says it can handle 5-10 watts input but I know that's crap. but even with less than 2 watts, the amps not swinging up to make power. with a deadkey of around 1.5w, it makes about 38w. On AM. With a deadkey of around 1.5, it makes about 23w. On SSB. With a 2w deadkey, it makes 60w on AM. and with a 2w deadkey makes about 30w on SSB. Send me a message and tell me what to do...If I need to get a bigger amp. I guess I'll start saving now...LOL

sonoma
02-03-2019, 11:43 PM
I am wondering if one of the mosfets in the amp has gone bad due to being over driven a little when the new radio was hooked up to it.
if you are thinking about getting a new amp I would buy a high drive amp. RM makes a amp I think is a 503 high drive. less chance of blowing it up with a single final radio that hits pretty hard. I have a few amps but just a fad when I bought them . tried them a few times than just put them in my closet.

sonoma
02-03-2019, 11:48 PM
here is the amp I am talking about.if you watch you can get them on sale about 20.00 cheaper and free shipping.

http://www.88radio.com/cb-amp?product_id=85

T-I-N-Y34
02-04-2019, 06:29 AM
here is the amp I am talking about.if you watch you can get them on sale about 20.00 cheaper and free shipping.

http://www.88radio.com/cb-amp?product_id=85
Well, it looks like I got to sell a guitar...lol