The ALH is a grounded grid linear Amplifier developed by Ameritron using low cost A power triodes. It operates in class AB2 for SSB. I’ve just been asked to fix an ALH by a local. but can’t find a Service Manual download anywhere (a main board layout would be useful). The ALH is rated at watts CW carrier in normal CW or tune. The AL is rated at watts PEP voice, or just over watts carrier.

Author: Yok Makinos
Country: Argentina
Language: English (Spanish)
Genre: Finance
Published (Last): 6 September 2017
Pages: 267
PDF File Size: 12.21 Mb
ePub File Size: 14.74 Mb
ISBN: 573-4-97122-356-8
Downloads: 4706
Price: Free* [*Free Regsitration Required]
Uploader: Yokree

ALC prevents over-driving of the linear and reduces distortion from excessive drive power. The administrator has the right to edit, move or remove any comment for any reason and without notice. I thought maybe the 2N had failed.

Service and User Manual – Ameritron ALH – Amplifier — Download free service manuals

The tubes are inexpensive and still, at the time of this writing, available. I wouldn’t supersize that diode, it is a weak link for a reason as I understand it.

Although the administrator will attempt to moderate comments, it is impossible for every comment to have been moderated at any given time. In some cases, not as easily serviceable as they could have been, but then what is? I don’t know what they were thinking.


Given its damage in the depicted tubeI think it’s caused by parasitic oscillationswhich led to a high voltage. This versatile Ameritron feature allows the user to maintain optimum voltages on the tubes and other components to obtain maximum performance and life.

Faulty Ameritron ALH | QRZ Forums

A Pi-Network tuned input matches the A tubes to 50 ohm exciters. When it first sergice, I installed the tubes, did the meter mod, and got on the air. W1QJAug 2, AF6LJAug 1, G3YROAug 1, More items related to this product. Fast Warm Up Time: Irregularities in the schematic.

Faulty Ameritron AL-811H

No wonder so many people on here are advised not to get one. However, here are photos of the circuit boards, one for the earlier version and one for the later version. I don’t know if there is even a “service” manual available for the ALH.

The drive level is detected to provide a control voltage for the exciter.

Flashover in a tube of an unprotected RF amplifier. In reality, no way to predict how the circuits actually behave. I soldered this to the spot on the band-switch that hadn’t been soldered, and its been flawless since. The A tubes take approximately 10 seconds to warm-up. It is a cheapsimple and proven effective method. The shielding of the cable is only grounded at the side of C That ‘s nothing compared to a deceased tubediodes, or worse a faulty transformer.


After each modification the amplifier was firmly tested and plates never becames red. I am wondering why you say the amp is awfully made. With this methodthe distance between S1 and C26 changed to a small capacitance in parallel with the load capacitor and the total inductance of the coil 10 m is thereby reduced.

It’s a well designed amp at a reasonable price and should provide many years of service. By submitting a comment, you are declaring that you agree with these rules: What a horrible linear amplifier! However, it’s as if the Valves are getting no drive on Transmit.