Tuning a 811 amp's Pie

[airplane1]

Hi all, I need instruction on tuning of the slugs at the back of the amp. The manual says nothing on this. I ask because I get a higher swr on 10 meter when amp is on and want it tuned in.

AP

 

[Beetle]

You'll have to use a non-metallic (very important) hex wrench. I believe it's 0.10". Then, with the amplifier turned on and operating into a dummy load, you tweak the 10M slug while watching the SWR indicator on the radio or somewhere before the amplifier. DON'T adjust any of the other slugs; they won't have any effect on 10M.

 

[wavrider]

How much of a mismatch are you getting on 10 meters?

 

[airplane1]

It seems off by 1.5 or so. I did npt try on any other bands because my ant is tuned for 1.1 on 10 so I can use the amp on 10 meter but the other bands are not tuned unless I use my tuner and it is only rated at 100 watts.

Can I do the dummy load adjustment on all bands bands to make sure they are all tuned.

AP

 

[W5LZ]

Yes, you should be able to use a dummy load on any band.
- 'Doc

 

[Beetle]

Out of curiosity and referring to your posting on another thread: when you say you "get a higher SWR on 10 meter when amp is on", are you measuring SWR after the amplifier/before the tuner, or before the amplifier? You should have metering in both places.

 

[airplane1]

I have the meter after the amp but before the tuner.

 

[airplane1]

Oh, I have the meter after the amp and before the tuner so I have a means to tune my amp. The meter shows 1.1/1.2 on 10 meterwith or without amp running. I have an IC-7000 which has a meter built in that is showing the same as the meter after the amp except when the amp is running the meter in the 7000 goes up, only when amp is running. So I want to tune the slug so it shows 1.1/1.2 on radio's meter.

When using a dummy load shouls I tune the amp just as I would on 10 meter and then key and tune the slug or just hook it to the dummy load and turn amp on and ????

I am sorry but I am getting myself messed up here.

I need to find some of the plastic tools as stated in this post, think Ameritron sells the tools?

Thanks,
AP

 

[wavrider]

Checking input VSWR on amp is same as checking VSWR on antenna.

Here is configuration for connecting and seeing what exactly is your input VSWR

rig-swr meter-amplifier-power meter-dummy load.

Connect in that config, tune the amp in accordance with the manufactures manual tune up procedures.

Once tuned then check the INPUT VSWR with the VSWR meter between your radio and amplifier.

If your rig has a built in vswr indication you can use it instead of the external VSWR meter, but verify the rig meter reading using an external to make sure it is some what accurate.

 

[Beetle]

I don't see the tool listed on Ameritron's website, but you might give them a call or email and see what they recommend.

Or, Google alignment tools electronic

...you'll find a bunch. As I said, I believe the size you need is a hexagonal tool, 0.1" across the flats (which would be 2.54mm - and 2.50mm should work nicely). I know I have three or four of them scattered around but I only know where ONE of them is.

 

[airplane1]

If your rig has a built in vswr indication you can use it instead of the external VSWR meter, but verify the rig meter reading using an external to make sure it is some what accurate.

I checked my rigs swr meter against the external swr/power meter and it matches very close if not exact so I use it instead of and external swr meter.

Thanks I will do a tune up on all my bands of the 811 amp with a dummy load so I know they are all smack on. Tha way once all is up and running and I get a new high power tuner I will be set to go.

Thanks a bunch for all the help,

AP

 

[airplane1]

I don't see the tool listed on Ameritron's website, but you might give them a call or email and see what they recommend.

Or, Google alignment tools electronic

...you'll find a bunch. As I said, I believe the size you need is a hexagonal tool, 0.1" across the flats (which would be 2.54mm - and 2.50mm should work nicely). I know I have three or four of them scattered around but I only know where ONE of them is.

Thanks, I am looking on line to buy some.

AP

 

[airplane1]

Yes, you should be able to use a dummy load on any band.
- 'Doc

Thank you Doc,

AP