The AM Forum

THE AM BULLETIN BOARD => Technical Forum => Topic started by: ka2zni on April 25, 2007, 11:06:19 AM



Title: AL-80A grid current meter problem
Post by: ka2zni on April 25, 2007, 11:06:19 AM
I should be more knowledgable about this stuff but, The grid current meter quit workin' all at once, the illumination bulbs on that meter are a tad bit brighter now, wondering if there was some simple fix to this or what would I need to check it? I thought maybe a multimeter and check across the terminals for current, other than that I do not have an idea and was wondering if anyone else has run into this problem..


Title: Re: AL-80A grid current meter problem
Post by: flintstone mop on April 25, 2007, 02:02:13 PM
If I remember, the grid current meter is also the plate current meter. You can download the scheezo from MFJ. Looks like a PC board involved to take the readings and drive the meters.

http://www.ameritron.com/man/pdf/AL-80B.pdf

Sorry I can't help you more.
Fred


Title: Re: AL-80A grid current meter problem
Post by: ka2zni on April 25, 2007, 06:14:20 PM
If I remember, the grid current meter is also the plate current meter. You can download the scheezo from MFJ. Looks like a PC board involved to take the readings and drive the meters.

http://www.ameritron.com/man/pdf/AL-80B.pdf

Sorry I can't help you more.
Fred

Thanks Fred.. Will give that a whirl..


Title: Re: AL-80A grid current meter problem
Post by: Pete, WA2CWA on April 25, 2007, 08:14:42 PM
Just a word of caution. The AL-80 version and AL-80A "early version" were made by Prime. The AL-80A MFJ later version had somewhat different circuitry than the "early" version made by Prime. Note: prior to Prime, the AL-80 was first made by Amp Supply.


Title: Re: AL-80A grid current meter problem
Post by: ka2zni on April 26, 2007, 01:38:03 PM
Thanks pete.. Yup lucky me... Model #27 so I am sure it is a prime edition... And no luck w/ the fix so will have to find someone that can work on these a little more comforatable than me, sometimes if you see the same trend over and over w/ same part it's an easy fix, and probably so for the right guy, but 'ole model #27 is going out to be fixed I think.. thanks for the input guys.


Title: Re: AL-80A grid current meter problem
Post by: Pete, WA2CWA on April 26, 2007, 02:13:31 PM
My good deed for the day, see attached meter board for Prime AL-80A.
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands