10/12 Meter Modification Instructions. AL (not A or B). The AL needs a kit to modify for 10/12 Meters. Write to us for details. All other units DO NOT require. Do the Ameritron H have to have the tuning coils adjusted when you do the 10 meter mod? I have not done the mod on my H and. the al & h mod is SIMPLE. you cut 1 wire for the meter mod, you will need to adjust input coil (inside amp)for lowest swr. if you do.

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W8JI does not include these steps, but the tubes are expensive. Then I tested merer output power on various bands, and let the plates get hot with a lengthy SSB transmission at full specified power. I reference their source information as well.

This will result in excessive grid current. The cosmetics were 9 out of 10, but the electrical condition poor. W8JI had numerous exchanges over the parasitic choke design, and did extensive analysis with equipment I cannot afford. With this methodthe ameritrpn 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.


W8JI Ameritron ALH Modification Photos & Instructions

Because there size s little space was to the valve sockets. Contact the site with comments or questions. The Ameritron PC board listed above metee an easy install with no questions about stability. Then you can reinstall the tube socket sub chassis back into the main chassis with the 8 screws you removed from the bottom of the amplifier.

Please note that the output in the table is partly achieved by exceeding the maximum grid and anode current. Once again, if you are new to the hobby, buy a NEW amp with a warranty and known good burned in tubes.

First, the tubes were bad. The resistor limits the rise time of the current from the capacitor bank into the arc. Within a decade, most amps will be using FETs.

Ameritron AL-811H 10m Mod

I have know idea. My friend bought the new PC board assembly for the parasitic chokes and some new tubes. If you obtain watts CW, it is in spec. Now, I would have gone with the ALS for better 10 meter output. Use a test clip to jumper the open contacts. Drill a hole just large enough for a mounting screw. W8JI arrows on his photo states: If you buy one, you will spend nearly as much as you did on your Ameritron ALH.


Which green wire is it? Go to the W8JI page and print these pages out: They are all the same age.

After each modification the amplifier was firmly tested and plates never becames red. Installing a pair of ohm resistors requires redesign of the input matching network, as W8JI notes. It is much better to avoid this, but there is a procedure to align them if you mess it up.

Possibly your results will be better, if you use tubes from those suppliers. Merer can see a close up of one of them, from the filament to the NEW grounding lug at the top of amerktron photo.

ALH 10/12 meter mod

With a solid state amplifier, you do not put your transceiver at risk if a tube arcs; there are no tubes and therefore no need for all these modifications. Support them with your business. Then try normal SSB operation.