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[VK3XZ]

Hi I am recently acquired 2 Dentron MLA2500 Amplifiers. One is an A model, I have the manual for it, But the MLA2500B Model I cannot
locate the manual on the web. Also I can see differences between A and B but no description of the differences. Could someone please tell
me the difference and provide a source for the missing MLA2500B operating manual. I have purchase these from a Deceased Estate where the paperwork was Missing. I really would like to know the difference and which Manuals I require. My email for vk3xz is good at QRZ.com. I am an Advanced Class Ham in Australia ( originally USA call WD5BQM in 1974. I am in Australia Countryside so not much help around. I would be most grateful if someone could please help to get these back on air! I am interested in 40,80 and 160 Meters Rag chewing!! I am going away from digital as it has become very boring. I have a Full Size End-fed(80 Meters long) at a height of 15 Meters. I hope someone could help me to gain this information. 72 vk3xz  vk4sy located in Outback Queensland Australia

[AE0Q]

Hi I am recently acquired 2 Dentron MLA2500 Amplifiers. One is an A model, I have the manual for it, But the MLA2500B Model I cannot locate the manual on the web.

Looks like both manuals are here on the Boat Anchor Manual Archive:

https://bama.edebris.com/manuals/dentron/mla2500/

Many, MANY equipment manuals are here, free.

Glenn AE0Q

[KA4WJA]

Mike,
In addition to Glenn pointing you to the manuals, I'll add a few tidbits that may be of interest (help?)...

Watch your Grid Current!
Except for a quick check of other items, leave the meter showing "Grid Current"....and be cautious when tuning-up...
(I haven't read the manuals, but like all other GG triode amps, you'll tune for max output, while maintaining lowest grid current possible)

Hi I am recently acquired 2 Dentron MLA2500 Amplifiers.

<snip>

I would be most grateful if someone could please help to get these back on air! I am interested in 40,80 and 160 Meters Rag chewing!!

 I am going away from digital as it has become very boring. I have a Full Size End-fed(80 Meters long) at a height of 15 Meters. I hope someone could help me to gain this information. 72 vk3xz  vk4sy located in Outback Queensland Australia

1)  Although the 8875's in the MLA-2500's are internally the same as 8874's (and are not as fragile as some think....much better than their bigger brother, the 3cx800!), they are almost unobtainable these days!   (I bought NOS Eimac 8874's this past year, for just a few dollars more than Chinese 3-500z's....and I could've spent 3 times that on NEW 8874's.....but, I haven't even seen 8875's for over a decade....so, they are rare, and you should be aware of that!)

2)  Denny, the founder of Dentron, is still alive and well, living in North Carolina (I think), and Tom, W8JI (who used to work for him) is also alive and well (in Georgia)....so, if you do find some difficulty in figuring things out, an email or two might get you what you need.

3)  Although I don't know where the user groups, etc., are at (do a Google search, or ask around here and on qrz.com)....there are still some old timers that are found of the old Dentrons, and even those that are not found of them will surely help you out here on eham or on qrz.com


Wishing you good luck!
(and remember, watch your Grid Current...don't panic about it, just monitor it...hi hi)

73,
John,  KA4WJA


P.S.  The usual caution about old dried-out caps, and worn switches, etc., all apply....as you've seen already, these amps will built to a low-price-point (they were marketed to the guys who could never afford a Drake L4-B, etc., let alone an Alpha)....and I believe were fairly "hand-built", so you may find some odd differences here-n-there....
Good luck!
73, John

[VE7RF]

AFAIK, neither version has a grid overcurrent circuit. The earlier model did not have a tuned input.  Tubes are unobtanium.
The amplifier, with no tubes or bad tubes sells for next to nothing.   Several have been converted to russian tubes.