|
All,
Question for the group. I am working on an Ameritron AL-80 (not A or B). When tuning it up I run out of load. I max the load cap out at zero on all bands. (fully meshed/max capacitance). It behaves the same on a two different dummy loads so I believe it to be an issue with the amp. Before I add another doorknob across the load cap, I figured I would ask the group for other ideas.
--
73 Nick KC0YKO
|
Nick,it seems as though you may have a poor connection somewhere inside the realm of the tank circuit. ?This could be at the band switch, the connections of the coils to the variables or just about anywhere, so make sure of all mechanical and soldered connections. ?Above 4 meters there are no padding cap issues so it’s got to be something like that. ?Also be sure there is no slippage on any of the connections to the variable capacitor shafis! ?Good luck
On Sunday, December 10, 2023, 9:41 AM, Nick Jones KC0YKO <kc0yko@...> wrote: All,
Question for the group. I am working on an Ameritron AL-80 (not A or B). When tuning it up I run out of load. I max the load cap out at zero on all bands. (fully meshed/max capacitance). It behaves the same on a two different dummy loads so I believe it to be an issue with the amp. Before I add another doorknob across the load cap, I figured I would ask the group for other ideas.
--
73 Nick KC0YKO
|
Is the band switch in good condition, in the correct position?
On Sunday, December 10, 2023 at 09:41:10 AM EST, Nick Jones KC0YKO <kc0yko@...> wrote:
All,
Question for the group. I am working on an Ameritron AL-80 (not A or B). When tuning it up I run out of load. I max the load cap out at zero on all bands. (fully meshed/max capacitance). It behaves the same on a two different dummy loads so I believe it to be an issue with the amp. Before I add another doorknob across the load cap, I figured I would ask the group for other ideas.
--
73 Nick KC0YKO
|
Thanks for all of the reply. I will check the connections within the tank circuit. The band switch looks OK but I will investigate closer. Band switch is in the correct position when testing.
--
73 Nick KC0YKO
|
I'm curious, how much drive are you driving it with? Constant carrier drive? How much power out? Ig and Ip?? Bob W4JFA?
On Sun, Dec 10, 2023, 9:41 AM Nick Jones KC0YKO < kc0yko@...> wrote: All,
Question for the group. I am working on an Ameritron AL-80 (not A or B). When tuning it up I run out of load. I max the load cap out at zero on all bands. (fully meshed/max capacitance). It behaves the same on a two different dummy loads so I believe it to be an issue with the amp. Before I add another doorknob across the load cap, I figured I would ask the group for other ideas.
--
73 Nick KC0YKO
|
Does the group have a source for the progressive shorting band switch wafer on the AL-80?
--
73 Nick KC0YKO
|
This reflector allows photos; it might help if you showed a photo
of the wafer you need, as well as the spacing between mounting
holes and the total number of positions.
But I wonder if MFJ doesn't sell that switch by itself?? They
seem to be attempting to cater to we DIYers with some small amount
of parts availability.
73,
Steve K0XP
On 12/11/2023 4:04 AM, Nick Jones
KC0YKO wrote:
Does the group have a source for the progressive shorting band
switch wafer on the AL-80?
--
73 Nick KC0YKO
--
See my QRZ.com page at
|
It appears the padder(s) are not being switched in on 40-80-160m.? BUT u have the issue on all bands.? It's as though the load cap isn't even in the circuit, or lousy tank coil coil connections.
|
Jim, I have one of these amps. With low drive from the exciter, the "load" will often end up all the way left/meshed. That's why I asked the op that. Bob W4JFA?
On Mon, Dec 11, 2023, 11:50 AM Jim VE7RF < jim.thom@...> wrote: It appears the padder(s) are not being switched in on 40-80-160m.? BUT u have the issue on all bands.? It's as though the load cap isn't even in the circuit, or lousy tank coil coil connections.
|
I had one of the first AL-80s quite a while ago.? It was very good at vaporizing one of the bandswitch contacts when operating on 160.??
|
On 12/11/2023 1:47 PM, Floyd - K8AC wrote: I had one of the first AL-80s quite a while ago.? It was very good at vaporizing one of the bandswitch contacts when operating on 160. So, did they fix the problem, and if so, how?? Heftier contacts or bandswitch? 73, Steve K0XP
|
I was told, years ago, after experiencing the same malady in a Yeasu 2100 by a more experienced ham (sic) to never change bands with the amplifier on.? Seemed sorta silly? to me.? I heard later on in my journeys’ down ham’s road, that was only true when changing the band switch to 160. ? I’ve never had a band switch problem, but let me tell you about the T/R relays in an AL-82…….I actually have 4 in my cupboard, just in case.? I have been through 5 already on a 3 year old amplifier.? L? I can even do it now without getting shocked!? J ? Joe – W7RKN From: [email protected] [mailto:[email protected]] On Behalf Of Floyd - K8AC
Subject: Re: [ham-amplifiers] Ameritron AL-80 (Not A or B) ? I had one of the first AL-80s quite a while ago.? It was very good at vaporizing one of the bandswitch contacts when operating on 160.??
|
It's been over 40 years ago I believe, but I think the final solution was to wrap a solid wire several turns around the contact where the wire was soldered.? There were sharp points that made it subject to corona discharge.? Mine was fixed a couple of times under warranty and I lived just 30-40 miles from the company so didn't have to ship it.
73, Floyd - K8AC
|
#8 brass washer over the terminal.
On Monday, December 11, 2023, 7:17 PM, Floyd - K8AC <floydsense@...> wrote: It's been over 40 years ago I believe, but I think the final solution was to wrap a solid wire several turns around the contact where the wire was soldered.? There were sharp points that made it subject to corona discharge.? Mine was fixed a couple of times under warranty and I lived just 30-40 miles from the company so didn't have to ship it.
73, Floyd - K8AC
|
Bob,
45-50 watts in for 350-400 out
toggle quoted message
Show quoted text
Jim, I have one of these amps. With low drive from the exciter, the "load" will often end up all the way left/meshed. That's why I asked the op that.
Bob W4JFA?
On Mon, Dec 11, 2023, 11:50 AM Jim VE7RF < jim.thom@...> wrote:
It appears the padder(s) are not being switched in on 40-80-160m.? BUT u have the issue on all bands.? It's as though the load cap isn't even in the circuit, or lousy tank coil coil connections.
-- 73 Nick KC0YKO
|
What do you guys think about the correction kit sold for AL-80B?
73,?
Tony
|
Nick Jones KC0YKO
Bob
Floyd - K8AC