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2510 am question

tvrc18

Active Member
May 1, 2011
178
5
28
I was setting up my 2510 with my 2 transistor amp and lowered the am output down to about 7 or 8 watts on my watt meter. I noticed when your doing the old audioooo test etc the watt meter drops a little with the amp on or off. Of course it is more noticable with the amp on and you can see a slight watt drop off when modulating. The radio has not been played with because I bought it new in the box but it is 20 years old or so. Is this normal or does it need an alignment or something? I have only used am maybe once and normally talk ssb.
 

Sounds like your power supply is not able to deliver enough current, so your signal is "back-swinging."

Assuming the radio, amp and PS are all up to specs, the only way to fix this is to use a PS that is rated for more current than is actually needed.

Hope this helps. :)
 
Unless you have a High Drive amp, you need to lower the dead key out of the radio down to 2-4 watts...whatever the amp seems to like. Usually never more than 4 watts on a Low Drive transistor amp.

2510's are also known for low factory modulation so try a power mic on it.

Good luck
 
What kind of amp is it?
If you can run the amp and the radio on the same power supply, and it is still dropping power with just the radio on i doubt the radio alone is starving.
If you tell us a little more, what kind of power supply , how big the power supply is ( how many amps ) what kind of Amp, what transistors it is using and so on it will help.
It might be as simple as adjusting the AMC control up just a tad.
If it has not be opened that is a good thing, it is easy for a screwdriver expert to twist the life out of them.


73
Jeff

( I never could understand why the first thing you find missing in a Hr2510 is the little paper stickers over the slugs that say " Do Not Tune" )
 
I run the 2510 on a Pyramid 21 amp power supply and it never seems to draw more than about 5 amps. The amp is a Cobra xl350 with 2 2879's and I run it with a 35 amp switching supply. The radio does it a little with the amp off also, I can see the watt meter drop off maybe a watt without the amp with modulation. I marked were the amc was adjusted and tried it with different settings and it did not seem to make much difference unless you turned it so far down you could barely get the meter to move when set to modulation on the 2510 meter. The amc was factory set to about mid point. I put it back to that setting. I noticed with the mic gain button pushed in it did not seem to drop off if I remember correctly.
 
A 35 amp supply should be fine for that amplifier as long as it's working as it should. You will need to set the AM dead key on the radio for about 2 watts with that amp. As stated, 7-8 watts dead key is way way too much.
 
Each transistor has a max input of 10 watts I think so I figured 7 or 8 would be fine, less than 5 for each. On ssb I have about 15 watts for the drive. Is that two much for ssb?
 
In my mobile, I have my Lincoln DK set between 2 & 3 watts, feeding a T/S DX350 (2X2879's). Seems to be the sweet spot.
Also, wouldn't hurt to send the radio to Rogerbird to give it the once over. Rogerbird is "Best-in-the-Land" on the HR2510/Lincoln radios.

JMO
 
Radio should not hiccup by itself.
The radio alone "should" be able to sustain A 8 Watt key with "some" forward swing....not a lot in the stock configuration but it should hold its own.
I do agree That Amp would like a lower dead key, but the radio should not back up alone.
What kind of meter?
I Am starting to suspect the meter may be reading off, and your dead key is higher than you think......lower the AM carrier to about 3 or 4 watts and look at the result..... you may need to adjust the AMC again.
Stock Mic?


73
Jeff
 
I am also thinking my radio shack meter is suspect. I have another post asking about swing because I never see a forward swing on am with the meter in the pep position on any of my radios. I did see a backswing however like this post is about. I have had it since the 80's. After looking again with out the amp on the needle maybe bounces a slight amount but hard to say because it is small and my eyes are not what they once were. It deffinetly does not swing forward like the meter is in the average position maybe. I guess it could be stuck in that mode. I need to try another meter. I am using the stock mic because my Turner +3 seems to much for the radio and is just to touchy to tone adjustments. I like the little rat shack meter, has 3 power settings up to 2000 watts and swr seems pretty accurate, but maybe it has lived its useful life.
 
The radio shack meters are OK for what they are, but they are not active peak reading meters, and the PEP setting is deceptive.
Having said that I have a old dual face R/S meter I have had for many years, it is fine for AVG watts and after a while it all gets relative to me anyway.
The Hr2510 is not a monster audio radio on AM, that is just the way they are built, however it should show some forward and the built in Mod Meter should show that you are getting close to 100% modulation if you have adjusted the AMC control.
Go ahead and reduce the carrier into the amp and see if it will show at least some forward swing.
But if you are not seeing ANY forward with any radio, might be time to look for a new meter.
If the Mod is indeed low, you can lift the emitter leg of of Q114, and put a 1K ohm resistor in series with the leg to the board, Rogerbird has this mod listed on his page.
This will pad the AMC threshold a bit and allow you to get more modulation.
To be honest with you, out of 2 Lincolns, A Hr2510, and A Hr2600 I have never had to do the Mod, I have always had good results by just adjusting the AMC....but each radio can vary a bit.


73
jeff
 
I lowered the the output to about 5 watts and it still swings a little backwards. That makes me think the meter may be questionable. I was seeing about 175 out on high with that setting. It did lower the amps output a small amount. Is the PEP on the radio shack meter not going to show a forward swing since like you say it is not an active meter? I did notice if the mic gain is depressed it does not swing backwards, not sure what that means. The radio meter swings up a little under modulation set to rf and set to modulation just hits the top of the scale.
 
Pushing in on the Mic button should lower the amount of audio.
the radio is saying you have modulation on the mod meter, and it also says you are increasing power when you talk.
The meter may be getting tired.
Try this.
Set the meter on SWR, and switch it to Forward or Set( i can not remember how the switches are marked).
Adjust the knob so that it reads Mid scale, about half way up.
Dead key the radio, and see if the meter moves up, while still in the forward Or Set setting when you talk into the Mic.



73
Jeff
 

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