AL_572

[KT7DAD]

I have an Ameritron AL-572.
I need to tune the input circuits to match my radio.

There is no instructions in the manual.

Do I need a special tool?

[KO6WB]

A plastic tuning tool .1 inch hex head is used. It's available from Ameritron for about $3.00 or if you have a local electronic dealer you can get a whole kit for around $8.00. Do not use a metal hex wrench. That can cause the slug in the coil to fracture and seize. You would then have to break it apart and remove it piece by piece and then insert the new slug.
The input SWR of the AL-572 should already be about 1.5:1 or lower. If it isn't then check the coax jumper between the rig and the amplifier. I had my AL-811 show a high SWR on 80/75. I got out the tuning tool to fix it and put a SWR meter into the line as a measurement of the tuning. To my surprise it was already within range where before it was 2.5:1. I put everything back and the SWR returned to 2.5:1. I then used a longer jumper between the rig and the amplifier and that fixed it.
Hope this helps
73
Gary

[AG6K]

I have an Ameritron AL-572.
I need to tune the input circuits to match my radio.

There is no instructions in the manual.

Do I need a special tool?

 Before you undertake this project you would do well to insure that each tuned circuit has a Q of 2 to 3 -- i.e., the input C on the Pi-network has a reactance of 17Ωs to 25Ωs on each band.

[AF6LJ]

A plastic tuning tool .1 inch hex head is used. It's available from Ameritron for about $3.00 or if you have a local electronic dealer you can get a whole kit for around $8.00. Do not use a metal hex wrench. That can cause the slug in the coil to fracture and seize. You would then have to break it apart and remove it piece by piece and then insert the new slug.
The input SWR of the AL-572 should already be about 1.5:1 or lower. If it isn't then check the coax jumper between the rig and the amplifier. I had my AL-811 show a high SWR on 80/75. I got out the tuning tool to fix it and put a SWR meter into the line as a measurement of the tuning. To my surprise it was already within range where before it was 2.5:1. I put everything back and the SWR returned to 2.5:1. I then used a longer jumper between the rig and the amplifier and that fixed it.
Hope this helps
73
Gary

This is good advice to follow...
Keep in mind on the band switch positions that cover more than one band, you will only be able to obtain a good match on one of the two bands, not both...

[K1DNR]

This is good advice to follow...
Keep in mind on the band switch positions that cover more than one band, you will only be able to obtain a good match on one of the two bands, not both...

I bought a kit from a seller on Amazon with the previously mentioned plastic .1 inch hex head. I'm sorry I can't find the seller now. You won't get a good match for both bands on one position of the band switch.

Since I got my new rig, which has a tuner built-in, I use that to match the rig to the input of the amp on the WARC bands. There is nothing *wrong* with doing this.

[KC8VWM]

A plastic tuning tool .1 inch hex head is used. It's available from Ameritron for about $3.00 or if you have a local electronic dealer you can get a whole kit for around $8.00.
73
Gary

Word on the street is these tools are now getting hard to come by.