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Heterodyne Hil
Posted on Thursday, June 14, 2001 - 11:03 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

307,

I dug up my first amplifier out of a box in my parents basement this evening. It is an LDO (Long Distance Operator). I can't tell who made it because the front says...

LDO Long Distance Operator
Council Bluffs, Iowa 51501

On the back is a sticker that says...

L.D.O. Electronics, Inc.
Omaha, Nebraska
serial no. 22897

It is a 100 watt bilinear amplifier and has two MRF445A's inside. The outside controls include switches for, linear (ON/OFF), pre-amp (ON/OFF), mode (AM FM/CW SSB), modulation (RMS/PEP).

On the back there is a slot in the case that has "Band" 10, 15, 20, 40. So this unit was obviously a multi band HF ham amp. Whatever that was in that slot has since been removed.

This thing still works, and I can get around 80 swinging 120 with 3 watts in.

So, have you ever seen one before, worked on one? Any info about this relic?

Steve
181
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707
Posted on Friday, June 15, 2001 - 4:19 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I had one of those back in 1980 and talked all over the world with it. Gold case if I recall, and ran nice and cool at full output, nice solid power supply inside. It worked great with a Cobra 2000
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Heterodyne Hill
Posted on Sunday, June 17, 2001 - 1:27 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

707,

Yep, that's the one! I used mine with a 142 GTL and loved it...I still have it but it needs some minor repairs. When I switch on the pre-amp it cuts out the receive altogether.

Steve
181
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707
Posted on Wednesday, June 27, 2001 - 10:25 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I wonder if there are 22896 others still out there???? I want another one. You might try checking the preamp relay for carbonization, or maybe the preamp is just toasted. you could easily bypass the old one and get a new GaSFET amp in there and it'll really hear!.
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Dx431
Posted on Sunday, July 21, 2002 - 11:45 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hmmm.....I just picked up a LDO amp from a friend of mine, and it has the same problem. But I think I will let someone else look at it who knows more about it than I do. Would really like to have that preamp workin.
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Bvennink
New member
Username: Bvennink

Post Number: 2
Registered: 3-2005
Posted on Wednesday, February 01, 2006 - 11:05 pm:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

I had a LDO amp that was a base type. It took two 17KV6A tubes. I believe they were sold out of the old Interstate Two-Way Radio shop in Council Bluffs IA. I think it is now called Larry's Diesel Repair, I think they also go by Jim Hawk trailers.
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Kid_vicious
Senior Member
Username: Kid_vicious

Post Number: 1132
Registered: 9-2004
Posted on Thursday, February 02, 2006 - 12:17 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

bvennink, welcome to the forum!

this is an archived message that you have responded to, and in an effort to save bandwidth, we usually try to start new threads rather than reactivate old ones.
when you bring a topic such as this back to the top, it makes the moderators life very difficult.
just thought i'd let you know before you get carried away and incurr the "wrath" of the mods.

we are always interested in discussing amps and everything else radio, so feel free to start a thread about anything.
you could even call it
bvennink's favorite amps etc..
have fun,
matt
CEF 410
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Swanbomb
New member
Username: Swanbomb

Post Number: 2
Registered: 3-2015
Posted on Wednesday, March 18, 2015 - 12:18 am:   Edit Post Delete Post    Move Post (Moderator/Admin Only)

Hey guys. Just got one of the same amps described earlier. I was wondering if it would be at all possible to use with my CB and also if you could tell me the correct position of the switches,

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