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Ca346
Posted on Thursday, November 13, 2003 - 11:33 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Has anyone done this mod to their President HR2510?

"http://rogerbird.tripod.com/2510vari.htm"

It appears to change the use and purpose of the SWR potentiometer knob to a variable power knob?

Feedback on whether it was worth it or not?
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Znut
Posted on Friday, November 14, 2003 - 10:13 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I did it and I'm not thrilled. It decreased the max output by about 15%. Also, the mod gets wierd when you turn the power way down. However, I'm still playing with it.

If you are going to try it, don't take the wires off the swr cal pot, just hook it to a 10k pot and hang the wires out of the mounting holes first and see if you like the results before doing it permanently.
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Scrapiron63
Posted on Friday, November 14, 2003 - 12:27 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

A tech here where I live use to do his own mod, I had several he had done and they worked good. Don't know just how it was done, but he was more or less just connecting the AM power adjustment pot to the SWR calibrate. It worked just on AM and the swr still worked, it would calibrate at about 4 watts. He would set them so the power would go from 1 watt to about 20. Made it good for matching to an amp. I've seen guys put a variable am power control on the side of the 2510 also, it looks kinda funky, but works.
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Ca346
Posted on Friday, November 14, 2003 - 2:24 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

ZNUT:

Thank you for the feedback. It will be awhile before I try anything with this radio. It's working real well at the moment, and I don't want to mess it up! But I know the output needs to be a little lower on SSB for my amp (Galaxy 350W) to be working properly. But I keep the power way down all the time on the amp anyway right now. I'm averaging about 80W to 110W as necessary with the amp. Alot of time even less.

The feature I DO like, is the SWR calibration and adjustment. It really helped when I was trying to get my COPPER IMAX 2000 up and the output tweaked to maximum effeciency. I would hate to lose the SWR knob? Are you suggesting leaving the SWR knob alone and adding another seperate POT for the variable power modification?
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Ca346
Posted on Friday, November 14, 2003 - 3:48 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Scrap:

Now you got the wheels turning. If the power adjustement worked on the AM side it should also effect the SSB side, shouldn't it?

Your message got posted after I wrote the response to ZNUT.
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Scrapiron63
Posted on Friday, November 14, 2003 - 9:14 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Ca346, the 2510 has an adjustment for AM and one for sideband. This is from memory as I don't have my book handy, but I believe they are marked and,
AM power is VR103, and SSB power is VR104.
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Ca346
Posted on Saturday, November 15, 2003 - 11:08 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Scrap:

Thanks. I will check it out. I want to turn the SSB down. You've got a pretty good memory to be able to state the VR numbers without a book handy?

I can't remember what I had for lunch yesterday.

Might be a radio weekend here. No sunshine. Cold (45 degrees). Fire in the woodstove. Lots of people talking on Channel 38LSB! bobman3
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Scrapiron63
Posted on Saturday, November 15, 2003 - 1:11 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hey 346, don't know why I remember those adjustments, but got them right. And I might not remember my phone number tomorrow. It shouldn't be any problem to turn the sideband down. I remember when the 2510s first came out, lots of people turned them all the way up on sideband, and they will hit 50 watts, well lots of the older solid state amps wouldn't stand that, some pills started popping. Some of the later amps will take more drive however.
I'm listening to 38 LSB now, 12:00 central, I hear a 459 out of California loud. scrapiron
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Ca346
Posted on Saturday, November 15, 2003 - 7:19 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Scrap:

Nice talking with you today on 38LSB, until bad conditions closed us out. Nice picture on your profile page. Too neat tho....
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Scrapiron63
Posted on Saturday, November 15, 2003 - 9:38 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hey, yeah it was good talking to you too, man we had good conditions for awhile. Maybe we can hook up tomorrow. Ha, I just cleaned that desk off for the picture, it doesn't usually look that neat.
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Flybynight
Posted on Tuesday, November 25, 2003 - 6:23 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Ca346,when that particular mod is done,it will adjust am/fm/ssb power as well.Adjust VR104 for maximum modulation.With the swr/cal turned all the way to the right,adjust am dead key for NO more than 10 to 15 watts.Also perform the mic gain mod.Which is to add a 1000ohm resistor between the emitter and where it solder's to the board of Q114.I have done a whole lot of 2510's like that.Havent had any trouble from the mod's either.The 2510 will perform best with a d104m6b/c mic.I dont think you will be dissapointed in the performance afterward's.
73's
Danny
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Ca346
Posted on Tuesday, November 25, 2003 - 8:56 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Fly:

Thanks for the response. I am already using a D104 with the HR2510. But it it such a great radio, I don't want to mess anything up with a hokey (love that word) modification. I will look at it closely and see what is best.

My new concern is in another area of the forum. KL-500 input power with another radio in the house.

Thanks again.

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