A lot of folks on this site do not understand the "Gettering process" !
Bringing a tube up to normal operating parameters is not gettering! I suggest
that these folks "Google" the gettering process before talking about it.
Willy Worth K3VW
In a message dated 9/12/2011 7:58:59 P.M. Eastern Daylight Time,
amps-request@contesting.com writes:
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Today's Topics:
1. Re: Alpha 76a (Patrick Barthelow)
2. Re: Alpha 76a (ROBERT HARMON)
3. Re: Alpha 76a (Colin Lamb)
4. Ameritron AL-80B ( s-roabr@online.no )
5. Re: Ameritron AL-80B (Mitch Cox)
6. Re: Alpha 76a (ROBERT HARMON)
7. Re: Alpha 76a (Alek Petkovic)
8. Re: Alpha 76a (Carl)
9. Re: Alpha 76a (Carl)
----------------------------------------------------------------------
Message: 1
Date: Mon, 12 Sep 2011 12:00:23 -0700
From: Patrick Barthelow <apolloeme@live.com>
Subject: Re: [Amps] Alpha 76a
To: <mikea@mikea.ath.cx>, <amps@contesting.com>
Message-ID: <SNT115-W43777F03CF113DFCDF7A8FDF020@phx.gbl>
Content-Type: text/plain; charset="iso-8859-1"
I received a 76A about 6 months ago, as a gift from a OOM who I helped a
lot when he was active. A 3 holer, that had been stored for some time, I
"gettered" it, slowly, bringing it back to life, without incident. On ALL
amps I have run, I am hyper aware and observant of grid current, in the
interest of long life, and note that Bob Wolbert has published a grid
overcurrent trip circuit for the Alpha, that might be wise to install. While
getting used to normal tuning dynamics of my New/old stock Alpha, I was
startled
somewhat at the grid current dynamics. At how quickly the Ig goes from
very low values to very high values with small adjustments of input power,
and tune and load controls, even with a good amount of loading. Perhaps
this is "normal" for a 3 holer '76A but maybe it is saying something about one
or more tubes. Other than that Ig sensitivity, the Alpha is the "AC
Cobra 427 " of amps, IMHO. and with winter coming up, if I operate QRO
with it, I will not
heed a shack heater, or a fire to cook marshmallows.
Best Regards,
Pat Barthelow AA6EG
> Date: Mon, 12 Sep 2011 13:31:22 -0500
> From: mikea@mikea.ath.cx
> To: amps@contesting.com
> Subject: Re: [Amps] Alpha 76a
>
> On Mon, Sep 12, 2011 at 11:20:33AM -0700, ROBERT HARMON wrote:
> > Charles,
> >
> >
> > I agree 100%. The Alpha 76PAC is one of the best amps ever made, a real
> > workhorse. Like a Timex watch, "takes a licking and keeps on ticking"
,
> > with one caveat, as you indicated, watch the grid current.
> > I run mine hard all the time (and keep a watchful eye on the grid
> > current)
> > Remember the "brick on the key" advertisements for these amps ? My
> > favorite is the ad used in 1981 which shows the usual heading of " Key
> > Down, How Long ?" and instead of the normally used brick on the key
there
> > is a skeleton sitting there with his hand on the key. Now thats a good
> > amp ! hihihi
>
> Erm ... As long as he's not wearing a nametag that reads "Ross Hull".
>
> --
> Mike Andrews, W5EGO
> mikea@mikea.ath.cx
> Tired old sysadmin
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
------------------------------
Message: 2
Date: Mon, 12 Sep 2011 13:23:52 -0700
From: ROBERT HARMON <k6uj@pacbell.net>
Subject: Re: [Amps] Alpha 76a
To: amps@contesting.com
Message-ID: <B3BED37F-5373-4E57-9AA0-924AB69B30ED@pacbell.net>
Content-Type: text/plain; charset=us-ascii
Pat,
Congratulations on acquiring the 76A, she will serve you well !
The grid overcurrent protection is a good idea. I am considering this for
my amp. Normally I keep
a close eye on the grid current but in the heat of battle during a contest
sometimes we lose our grip, hihi.
One thing you might consider if you haven't already is replacing the power
supply HV filter caps. They are more than ready
to be replaced if they are the originals.
73,
Bob
K6UJ
On Sep 12, 2011, at 12:00 PM, Patrick Barthelow wrote:
>
> I received a 76A about 6 months ago, as a gift from a OOM who I helped
a lot when he was active. A 3 holer, that had been stored for some time, I
"gettered" it, slowly, bringing it back to life, without incident. On ALL
amps I have run, I am hyper aware and observant of grid current, in the
interest of long life, and note that Bob Wolbert has published a grid
overcurrent trip circuit for the Alpha, that might be wise to install. While
getting used to normal tuning dynamics of my New/old stock Alpha, I was
startled somewhat at the grid current dynamics. At how quickly the Ig goes
from
very low values to very high values with small adjustments of input power,
and tune and load controls, even with a good amount of loading. Perhaps
this is "normal" for a 3 holer '76A but maybe it is saying something about
one or more tubes. Other than that Ig sensitivity, the Alpha is the "AC
Cobra 427 " of amps, IMHO. and with winter coming up, if I operate QRO
with it, I will no
t
> heed a shack heater, or a fire to cook marshmallows.
>
> Best Regards,
> Pat Barthelow AA6EG
>
>
>
>> Date: Mon, 12 Sep 2011 13:31:22 -0500
>> From: mikea@mikea.ath.cx
>> To: amps@contesting.com
>> Subject: Re: [Amps] Alpha 76a
>>
>> On Mon, Sep 12, 2011 at 11:20:33AM -0700, ROBERT HARMON wrote:
>>> Charles,
>>>
>>>
>>> I agree 100%. The Alpha 76PAC is one of the best amps ever made, a real
>>> workhorse. Like a Timex watch, "takes a licking and keeps on ticking" ,
>>> with one caveat, as you indicated, watch the grid current.
>>> I run mine hard all the time (and keep a watchful eye on the grid
>>> current)
>>> Remember the "brick on the key" advertisements for these amps ? My
>>> favorite is the ad used in 1981 which shows the usual heading of " Key
>>> Down, How Long ?" and instead of the normally used brick on the key
there
>>> is a skeleton sitting there with his hand on the key. Now thats a good
>>> amp ! hihihi
>>
>> Erm ... As long as he's not wearing a nametag that reads "Ross Hull".
>>
>> --
>> Mike Andrews, W5EGO
>> mikea@mikea.ath.cx
>> Tired old sysadmin
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
------------------------------
Message: 3
Date: Mon, 12 Sep 2011 13:43:26 -0700 (GMT-07:00)
From: Colin Lamb <k7fm@teleport.com>
Subject: Re: [Amps] Alpha 76a
To: amps@contesting.com
Message-ID:
<553556.1315860207266.JavaMail.root@mswamui-valley.atl.sa.earthlink.net>
Content-Type: text/plain; charset=UTF-8
"One thing you might consider if you haven't already is replacing the
power supply HV filter caps. They are more than ready One thing you might
consider if you haven't already is replacing the power supply HV filter caps."
Two weeks ago, I had my Alpha 76A apart and decided to check out the
electrolytics and bleeder resistors. I removed each capacitor and checked
them
with a capacitance meter and and ESR meter. I also measured the leakage
current under load. The amp had not been used for years, but after forming
for a few minutes, the leakage current dropped to almost nothing. Measured
capacitance was within a couple percent.
These caps are high quality original caps and did not need replacement.
Although I have found other amps that needed replacement caps, the Alphas
have held up well. Worthwhile to try them before replacement.
73, Colin K7FM
------------------------------
Message: 4
Date: Tue, 13 Sep 2011 00:18:09 +0200
From: " s-roabr@online.no " <s-roabr@online.no>
Subject: [Amps] Ameritron AL-80B
To: amps@contesting.com
Message-ID: <201109122218.p8CMIItZ002462@mail48.nsc.no>
Content-Type: text/plain; charset=utf-8
Hi
I have a AL-80B, all bands is ok. But it have max 300w on 10m. Any idea
how to find out why?
Any one have had same problem?
sent by HTC
LA6FJA K3RAG Stein Roar Brobakken
------------------------------
Message: 5
Date: Mon, 12 Sep 2011 18:36:14 -0400
From: "Mitch Cox" <ww4cox@embarqmail.com>
Subject: Re: [Amps] Ameritron AL-80B
To: <amps@contesting.com>, <s-roabr@online.no>
Message-ID: <A02EDA34558D4FB6AD5F7185E821346B@w4cox057538544>
Content-Type: text/plain; charset="iso-8859-1"
Have you looked at the SWR between the radio and amp on 10 meters?
----- Original Message -----
From: s-roabr@online.no
To: amps@contesting.com
Sent: Monday, September 12, 2011 6:18 PM
Subject: [Amps] Ameritron AL-80B
Hi
I have a AL-80B, all bands is ok. But it have max 300w on 10m. Any idea
how to find out why?
Any one have had same problem?
sent by HTC
LA6FJA K3RAG Stein Roar Brobakken
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------------------------------
Message: 6
Date: Mon, 12 Sep 2011 16:20:06 -0700
From: ROBERT HARMON <k6uj@pacbell.net>
Subject: Re: [Amps] Alpha 76a
To: amps@contesting.com
Message-ID: <468DF4D7-A377-4E19-83EF-A300193B49C9@pacbell.net>
Content-Type: text/plain; charset=us-ascii
Colin,
I didn't check the caps in my 76, I didn't see any evidence of swelling or
leaking when I visually inspected them
but since they were original I thought it would be prudent to replace them.
HV electrolytics have a life span of between 15-20yrs. They quit
producing the Alpha 76 series in 1985 so the original
76 series HV filter caps are at least 26 years old.
They probably would have lasted longer before failing but I felt it was
good preventive maintenance.
Replacing the cap bank is pretty easy. RF Parts has the original replaceme
nts.
Another PM item worth doing is lubing the fan. The 76 fan has a sleeve
bearing and a little lube will extend the life
and prevent the fan from getting noisy and needing replacement down the
road. (The original fans are no longer available.)
Remove the motor end cover and do several repeated applications of fine
machine oil like 3 in one oil. The shaft bearing is
a porous bronze alloy and will soak up a substantial amount of oil. The
motor end cover has an o-ring seal to prevent any oil from
leaking out.
Bob
K6UJ
On Sep 12, 2011, at 1:43 PM, Colin Lamb wrote:
> "One thing you might consider if you haven't already is replacing the
power supply HV filter caps. They are more than ready One thing you might
consider if you haven't already is replacing the power supply HV filter caps."
>
> Two weeks ago, I had my Alpha 76A apart and decided to check out the
electrolytics and bleeder resistors. I removed each capacitor and checked
them with a capacitance meter and and ESR meter. I also measured the leakage
current under load. The amp had not been used for years, but after forming
for a few minutes, the leakage current dropped to almost nothing.
Measured capacitance was within a couple percent.
>
> These caps are high quality original caps and did not need replacement.
Although I have found other amps that needed replacement caps, the Alphas
have held up well. Worthwhile to try them before replacement.
>
> 73, Colin K7FM
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
------------------------------
Message: 7
Date: Tue, 13 Sep 2011 07:36:46 +0800
From: Alek Petkovic <vk6apk@bigpond.com>
Subject: Re: [Amps] Alpha 76a
To: amps@contesting.com
Message-ID: <4E6E978E.6020407@bigpond.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
So, you are saying that, if you push it really hard, then it will easily
achieve Thailand's 200W PEP limit?
Plus headroom. :-) :-)
73, Alek. VK6APK.
On 12/09/2011 12:10 PM, Charles Harpole wrote:
> I have an Alpha 76PAC and IF you watch the grid, you can drive this amp
to 3kw out if u want.... This is one battleship amp, but too much grid,
over half scale is vy bad, will kill the tubes fast.Alpha always sez "No ALC."
I agree. ALC is for whimps. Please, gentlemen and ladies, your radios
ARE THERE TO USE, not to baby and fall in love with....they are things, not
people.DRIVE IT ....DRIVE IT... GO GO GO........... 73, Charles Harpole
k4vud@hotmail.com
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
--
http://www.qrz.com/db/vk6apk
http://www.qrz.com/db/vk6ap
=======
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------------------------------
Message: 8
Date: Mon, 12 Sep 2011 19:57:59 -0400
From: "Carl" <km1h@jeremy.mv.com>
Subject: Re: [Amps] Alpha 76a
To: "ROBERT HARMON" <k6uj@pacbell.net>, <amps@contesting.com>
Message-ID: <DBAC8A01CDCF4753A767C16A82095BD8@computer1>
Content-Type: text/plain; format=flowed; charset="Windows-1252";
reply-type=original
Mine is a 3 holer PA that had a hard former life in a Caribbean contest
station. It was given to me as payment for fixing their other amps and I
put
it back together as new....almost.
I run at 1200-1300W maximum and keep the grid current and drive as low as
possible to get there. Since it is the 2nd station amp it gets very light
duty except when chasing new ones on several bands.
The primary amp is still a LK-500ZC Ive had since 86.
While swapping to a pair of 3CX800's is simple enough even those are not
cheap as medical pulls and at some finite date Eimac will kill those also.
Carl
KM1H
----- Original Message -----
From: "ROBERT HARMON" <k6uj@pacbell.net>
To: <amps@contesting.com>
Sent: Monday, September 12, 2011 2:20 PM
Subject: Re: [Amps] Alpha 76a
Charles,
I agree 100%. The Alpha 76PAC is one of the best amps ever made, a real
workhorse. Like a Timex watch,
"takes a licking and keeps on ticking" , with one caveat, as you
indicated,
watch the grid current.
I run mine hard all the time (and keep a watchful eye on the grid current)
Remember the "brick on the key" advertisements for these amps ? My
favorite
is the ad used in 1981
which shows the usual heading of " Key Down, How Long ?" and instead of
the
normally used brick on the
key there is a skeleton sitting there with his hand on the key. Now thats
a
good amp ! hihihi
73,
Bob
K6UJ
Alpha ?brick on the key? durability. If you are looking for a good used
entry level amp, it's hard to go wrong with this old work horse. I
personally would like to see Alpha bring this amp back into production,
the
simplicity of analog metering with basic controls is the way to go. The
?over use? of LED metering electronics just adds to the cost.
On Sep 11, 2011, at 9:10 PM, Charles Harpole wrote:
>
> I have an Alpha 76PAC and IF you watch the grid, you can drive this amp
to
> 3kw out if u want.... This is one battleship amp, but too much grid,
over
> half scale is vy bad, will kill the tubes fast.Alpha always sez "No
ALC."
> I agree. ALC is for whimps. Please, gentlemen and ladies, your radios
> ARE THERE TO USE, not to baby and fall in love with....they are things,
> not people.DRIVE IT ....DRIVE IT... GO GO GO........... 73, Charles
> Harpole k4vud@hotmail.com
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
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-----
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------------------------------
Message: 9
Date: Mon, 12 Sep 2011 19:58:32 -0400
From: "Carl" <km1h@jeremy.mv.com>
Subject: Re: [Amps] Alpha 76a
To: "Colin Lamb" <k7fm@teleport.com>, <amps@contesting.com>
Message-ID: <54A580D44C544F40968C89B869A23E3A@computer1>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I dont trust any electrolytic that is 30 or so years old. At $13 and
change
each I bought new ones from Ameritron and also replaced the equalizers.
A big problem with many 76's is the C-109 tantalum, C-108 electrolytic,
R-116 (go to a 1W), and R-124 a 2W carbon that drifts up in value to the
point K-6 never activates.
Carl
KM1H
----- Original Message -----
From: "Colin Lamb" <k7fm@teleport.com>
To: <amps@contesting.com>
Sent: Monday, September 12, 2011 4:43 PM
Subject: Re: [Amps] Alpha 76a
> "One thing you might consider if you haven't already is replacing the
> power supply HV filter caps. They are more than ready One thing you
might
> consider if you haven't already is replacing the power supply HV filter
> caps."
>
> Two weeks ago, I had my Alpha 76A apart and decided to check out the
> electrolytics and bleeder resistors. I removed each capacitor and
checked
> them with a capacitance meter and and ESR meter. I also measured the
> leakage current under load. The amp had not been used for years, but
> after forming for a few minutes, the leakage current dropped to almost
> nothing. Measured capacitance was within a couple percent.
>
> These caps are high quality original caps and did not need replacement.
> Although I have found other amps that needed replacement caps, the
Alphas
> have held up well. Worthwhile to try them before replacement.
>
> 73, Colin K7FM
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1392 / Virus Database: 1520/3892 - Release Date: 09/12/11
>
------------------------------
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End of Amps Digest, Vol 105, Issue 9
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