View and Download AMERITRON ALH instruction manual online. HF POWER LINEAR AMPLIFIER. ALH Amplifier pdf manual download. Manuals and User Guides for AMERITRON ALH. We have 1 AMERITRON ALH manual available for free PDF download: Instruction Manual. Download AMERITRON ALH 1,,5MHZ LINEAR AMPLIFIER SM service manual & repair info for electronics experts.

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G3YROAug 1, On the other bandthe SWR will be high and is an internal tuner required for full ouput. I think it had a Valve flashover before I got it. The energy could not leave via the high impedance of amefitron plate circuitand so chose the shortest path via the a,eritron.
AF6LJAug 2, The shielding of the cable is only grounded at the side of C The long wire to be replaced by coaxial cable RGso that the length is converted into a small capacitance in parallel with the load capacitor. Any suggestions would be welcome. However, it’s as if the Valves are all-811h no drive on Transmit. I used as “earth” the screw at the bottom of the anode choke.
Test and adjust the SWR also on the other bands.

Not close to L4 but far away on the PSU board. However, here are photos of the circuit boards, one for the earlier version and one for the later version. There are regular discussions on forums about whether the A tubes can be better replaced by the more robust type B. Your name or email address: Can you site some issues you think are not good and how it can al-11h improved.
Connect the amplifier to a dummy load and adjust for maximum ouput. Turn per band load and plate control clock and anti clockwise and watch if there is any anode or grid current. After each modification the amplifier was firmly tested and plates never becames red.
AMERITRON AL-811H Instruction Manual
My preference would be given to the latter because I have more experience with it. Irregularities in the schematic. I believe it’s asking for troubleand it is better to shorten the RF path by installing an additional 4n7 capacitor at the lower end of L4.
The powerful spark induced scorching and inside a hole in the glass. I’m guessing it was designed at the Christmas party and they were all drunk. What a horrible linear amplifier! Ameritron never published service manuals for any of their amplifiers so they don’t exist. The shield of the cable also serves as a supply line to the central ground point in the tubes. The AL- H is sold worldwide and is quite a well-built “budget” amplifierbut by no means easy to repair.
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. This is a later model, by the way. You must log in or sign up to reply here. AF6LJAug 1, I’ve never seen one before. Please note that the output in the table is partly achieved by exceeding the maximum grid and anode current. Therefore, a sumiere test was done with the two types.
The Grid current meter was reading on transmit with no drive. A tentative conclusion is that this AL – H does not distort the signal of the drive stage.
K9STHAug 2, Given its damage in the depicted tubeI think it’s caused by parasitic oscillationswhich led to a high voltage. The inductance of the long supply wires can not be ignored. Yah bigger is better. Register for a free QRZ account.
ALH Modifications
Many thanks for that Glen. I don’t know if there is even a “service” manual available for the ALH. The size of the 10 m coil has become too small due to mounting method. No the meters are both OK.
For decadesI advise to mount a resistor and fuse in series with the anode choke as flash over protection for tubesrectifiers and transformers. The PA had no additional protection and had not been operational for years. The Ameritron amps I’ve seen aren’t poorly made. I assume there are no professional repair people around.
In reality, no way to predict how the circuits actually behave. I thought maybe the 2N had failed. No wonder so many people on here are advised not to get one. My inspection yielded a burned grid resistor and a partially conductive varistor on. I wouldn’t supersize that diode, it is a weak link for a reason as I understand it. I like TT gear in general, but their dual Z amp is about as “unserviceable” as any I’ve ever seen.

