Bill, Dave, Terry,
GM and excellent recollections of the techniques.
I responded direct to Ralph (yesterday).
As I am going through the documentation process, I found various images and
collet assemblies (in stock) - some for the same frequency. I now have good
info on the current designs. So, I will suspect that the # of fingers would
be the same for a 1 or 2 tube amp.
73,
Steve
W1SMS
Steven M. Simons
lunarlink@manitousys.com
Lunar-Link International
Tel.203.733.2110 Fax.203.746.1459
33 Ball Pond Road Danbury, CT 06811
Mailing Address: PO Box 8066 New Fairfield, CT 06812
FN31FK Lat 41.442718 Long -73.505777
-----Original Message-----
From: VHFcontesting [mailto:vhfcontesting-bounces@contesting.com] On Behalf
Of vhfcontesting-request@contesting.com
Sent: Wednesday, October 21, 2015 1:56 AM
To: vhfcontesting@contesting.com
Subject: VHFcontesting Digest, Vol 154, Issue 8
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Today's Topics:
1. Re: 3cx800a 222 amp (Bill Olson)
2. Re: 3cx800a 222 amp (Terry Price)
3. Re: 3cx800a 222 amp (Bill Olson)
4. Re: 3cx800a 222 amp (Dave Olean)
5. Re: 3cx800a 222 amp (David Pruett)
----------------------------------------------------------------------
Message: 1
Date: Tue, 20 Oct 2015 16:00:03 +0000
From: Bill Olson <callbill@hotmail.com>
To: VHF Contest Reflector <vhfcontesting@contesting.com>
Subject: Re: [VHFcontesting] 3cx800a 222 amp
Message-ID: <BAY177-W3BF04B5B4E9C0A7DCA231C6390@phx.gbl>
Content-Type: text/plain; charset="iso-8859-1"
Ralph, I'm really straining my brain here, but I seem to remember these
triodes wanted a little inductance in the cathode connection to "neutralize"
them. I remember with an 8874 on 220 back 35 or 40 years ago I build a home
made grid collet with finger stock.. The finger stock was in a solid ring at
first but in order to make the thing work I had to keep bending fingers away
from the grid ring on the tube.. That's all I remember, don't have that amp
any more..
Steve, W1SMS, now owns and runs Lunar Link, I'm sure he has the info you
want..
bill, k1DY
> Date: Tue, 20 Oct 2015 11:23:01 -0400
> From: mathenyr@marietta.edu
> To: vhfcontesting@contesting.com
> Subject: [VHFcontesting] 3cx800a 222 amp
>
>
>
> I remember reading that there was a K1FO 222 amp using a single
> 3xc800a7 tube. I have tired to get such an amp to behave without
> success...cathode circuit problems.
>
> Does anyone know if the K1FO amp description was ever published? Does
> anybody have one of the amps who could send me a copy of a manual or
> perhaps photos??
>
> Also looking for a proper grid collet for the thing...
> Eimac 720359 ... anybody know a source? The grid collet
> may be my problem, but I am on my second "hamstyle" version and
> getting frustrated.
>
> The 2M version of the thing worked first try....
>
> Thanks..
>
> de K8RYU
> _______________________________________________
> VHFcontesting mailing list
> VHFcontesting@contesting.com
> http://lists.contesting.com/mailman/listinfo/vhfcontesting
------------------------------
Message: 2
Date: Tue, 20 Oct 2015 12:39:16 -0400
From: "Terry Price" <w8zn54@verizon.net>
To: "'Bill Olson'" <callbill@hotmail.com>, "'VHF Contest Reflector'"
<vhfcontesting@contesting.com>
Subject: Re: [VHFcontesting] 3cx800a 222 amp
Message-ID: <158901d10b55$dc58d530$950a7f90$@verizon.net>
Content-Type: text/plain; charset=US-ASCII
I've built several 3CX800A7 222 amps and the cathode circuit that was used
on the 8874 version was the same. The plate line changed.
Terry - W8ZN
-----Original Message-----
From: VHFcontesting [mailto:vhfcontesting-bounces@contesting.com] On Behalf
Of Bill Olson
Sent: Tuesday, October 20, 2015 12:00 PM
To: VHF Contest Reflector
Subject: Re: [VHFcontesting] 3cx800a 222 amp
Ralph, I'm really straining my brain here, but I seem to remember these
triodes wanted a little inductance in the cathode connection to "neutralize"
them. I remember with an 8874 on 220 back 35 or 40 years ago I build a home
made grid collet with finger stock.. The finger stock was in a solid ring at
first but in order to make the thing work I had to keep bending fingers away
from the grid ring on the tube.. That's all I remember, don't have that amp
any more..
Steve, W1SMS, now owns and runs Lunar Link, I'm sure he has the info you
want..
bill, k1DY
> Date: Tue, 20 Oct 2015 11:23:01 -0400
> From: mathenyr@marietta.edu
> To: vhfcontesting@contesting.com
> Subject: [VHFcontesting] 3cx800a 222 amp
>
>
>
> I remember reading that there was a K1FO 222 amp using a single
> 3xc800a7 tube. I have tired to get such an amp to behave without
> success...cathode circuit problems.
>
> Does anyone know if the K1FO amp description was ever published? Does
> anybody have one of the amps who could send me a copy of a manual or
> perhaps photos??
>
> Also looking for a proper grid collet for the thing...
> Eimac 720359 ... anybody know a source? The grid collet
> may be my problem, but I am on my second "hamstyle" version and
> getting frustrated.
>
> The 2M version of the thing worked first try....
>
> Thanks..
>
> de K8RYU
> _______________________________________________
> VHFcontesting mailing list
> VHFcontesting@contesting.com
> http://lists.contesting.com/mailman/listinfo/vhfcontesting
_______________________________________________
VHFcontesting mailing list
VHFcontesting@contesting.com
http://lists.contesting.com/mailman/listinfo/vhfcontesting
------------------------------
Message: 3
Date: Tue, 20 Oct 2015 16:48:03 +0000
From: Bill Olson <callbill@hotmail.com>
To: terry price <w8zn54@verizon.net>, VHF Contest Reflector
<vhfcontesting@contesting.com>
Subject: Re: [VHFcontesting] 3cx800a 222 amp
Message-ID: <BAY177-W49321F235A2B205A5583CEC6390@phx.gbl>
Content-Type: text/plain; charset="iso-8859-1"
yeah, duh, I was talking about the grid collet!! so where I said "cathode
connection" was just me being stupid, what I MEANT was I seem to remember
there needed to be just a little inductance in the grid connection, so with
homebrew collets you had to diddle with the number of fingers a little..
bill
> From: w8zn54@verizon.net
> To: callbill@hotmail.com; vhfcontesting@contesting.com
> Date: Tue, 20 Oct 2015 12:39:16 -0400
> Subject: Re: [VHFcontesting] 3cx800a 222 amp
>
> I've built several 3CX800A7 222 amps and the cathode circuit that was
> used on the 8874 version was the same. The plate line changed.
>
> Terry - W8ZN
>
> -----Original Message-----
> From: VHFcontesting [mailto:vhfcontesting-bounces@contesting.com] On
> Behalf Of Bill Olson
> Sent: Tuesday, October 20, 2015 12:00 PM
> To: VHF Contest Reflector
> Subject: Re: [VHFcontesting] 3cx800a 222 amp
>
> Ralph, I'm really straining my brain here, but I seem to remember
> these triodes wanted a little inductance in the cathode connection to
"neutralize"
> them. I remember with an 8874 on 220 back 35 or 40 years ago I build a
> home made grid collet with finger stock.. The finger stock was in a
> solid ring at first but in order to make the thing work I had to keep
> bending fingers away from the grid ring on the tube.. That's all I
> remember, don't have that amp any more..
>
> Steve, W1SMS, now owns and runs Lunar Link, I'm sure he has the info
> you want..
>
> bill, k1DY
>
> > Date: Tue, 20 Oct 2015 11:23:01 -0400
> > From: mathenyr@marietta.edu
> > To: vhfcontesting@contesting.com
> > Subject: [VHFcontesting] 3cx800a 222 amp
> >
> >
> >
> > I remember reading that there was a K1FO 222 amp using a single
> > 3xc800a7 tube. I have tired to get such an amp to behave without
> > success...cathode circuit problems.
> >
> > Does anyone know if the K1FO amp description was ever published?
> > Does anybody have one of the amps who could send me a copy of a
> > manual or perhaps photos??
> >
> > Also looking for a proper grid collet for the thing...
> > Eimac 720359 ... anybody know a source? The grid collet
> > may be my problem, but I am on my second "hamstyle" version and
> > getting frustrated.
> >
> > The 2M version of the thing worked first try....
> >
> > Thanks..
> >
> > de K8RYU
> > _______________________________________________
> > VHFcontesting mailing list
> > VHFcontesting@contesting.com
> > http://lists.contesting.com/mailman/listinfo/vhfcontesting
>
> _______________________________________________
> VHFcontesting mailing list
> VHFcontesting@contesting.com
> http://lists.contesting.com/mailman/listinfo/vhfcontesting
>
> _______________________________________________
> VHFcontesting mailing list
> VHFcontesting@contesting.com
> http://lists.contesting.com/mailman/listinfo/vhfcontesting
------------------------------
Message: 4
Date: Tue, 20 Oct 2015 20:37:48 -0000
From: "Dave Olean" <k1whs@metrocast.net>
To: "Bill Olson" <callbill@hotmail.com>, "terry price"
<w8zn54@verizon.net>, "VHF Contest Reflector"
<vhfcontesting@contesting.com>
Subject: Re: [VHFcontesting] 3cx800a 222 amp
Message-ID: <166941A7946E487992558942426FC5C2@t30ce0d73e1b34>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Hi Bill et al.
The one I remember was the grid collet for the 8938 on 432. It needed a
slight bit of inductance for best neutralization. I remember that Steve
figured it out, although the amplifier worked fine without it, you would see
some drifting in the power output, no doubt due to some regeneration in the
grid crcuit. After removing a small number of fingers from the grounded
collet, the amplifier was much more stable as far as power output went. When
I got the tube initially, W6PO indicated that it had flunked the stable
power output test and was rejected for an order to the Swiss gov't. The
tubes were for remote unattended sites where the tubes would normally be off
until required and then had to reach full power from a cold start. Bob
indicated that with use the tube would probably improve and be just fine. I
did see power drift, which improved, but, by removing teeth from the finger
stock, it got really stable. Now I do not notice much drift at all. I think
Steve removed every fourth finger. I could always take the 432 KW apart and
look at the grid ring!
Dave K1WHS
----- Original Message -----
From: "Bill Olson" <callbill@hotmail.com>
To: "terry price" <w8zn54@verizon.net>; "VHF Contest Reflector"
<vhfcontesting@contesting.com>
Sent: Tuesday, October 20, 2015 4:48 PM
Subject: Re: [VHFcontesting] 3cx800a 222 amp
> yeah, duh, I was talking about the grid collet!! so where I said "cathode
> connection" was just me being stupid, what I MEANT was I seem to remember
> there needed to be just a little inductance in the grid connection, so
> with homebrew collets you had to diddle with the number of fingers a
> little..
>
> bill
>
>
>
>> From: w8zn54@verizon.net
>> To: callbill@hotmail.com; vhfcontesting@contesting.com
>> Date: Tue, 20 Oct 2015 12:39:16 -0400
>> Subject: Re: [VHFcontesting] 3cx800a 222 amp
>>
>> I've built several 3CX800A7 222 amps and the cathode circuit that was
>> used
>> on the 8874 version was the same. The plate line changed.
>>
>> Terry - W8ZN
>>
>> -----Original Message-----
>> From: VHFcontesting [mailto:vhfcontesting-bounces@contesting.com] On
>> Behalf
>> Of Bill Olson
>> Sent: Tuesday, October 20, 2015 12:00 PM
>> To: VHF Contest Reflector
>> Subject: Re: [VHFcontesting] 3cx800a 222 amp
>>
>> Ralph, I'm really straining my brain here, but I seem to remember these
>> triodes wanted a little inductance in the cathode connection to
>> "neutralize"
>> them. I remember with an 8874 on 220 back 35 or 40 years ago I build a
>> home
>> made grid collet with finger stock.. The finger stock was in a solid ring
>> at
>> first but in order to make the thing work I had to keep bending fingers
>> away
>> from the grid ring on the tube.. That's all I remember, don't have that
>> amp
>> any more..
>>
>> Steve, W1SMS, now owns and runs Lunar Link, I'm sure he has the info you
>> want..
>>
>> bill, k1DY
>>
>> > Date: Tue, 20 Oct 2015 11:23:01 -0400
>> > From: mathenyr@marietta.edu
>> > To: vhfcontesting@contesting.com
>> > Subject: [VHFcontesting] 3cx800a 222 amp
>> >
>> >
>> >
>> > I remember reading that there was a K1FO 222 amp using a single
>> > 3xc800a7 tube. I have tired to get such an amp to behave without
>> > success...cathode circuit problems.
>> >
>> > Does anyone know if the K1FO amp description was ever published? Does
>> > anybody have one of the amps who could send me a copy of a manual or
>> > perhaps photos??
>> >
>> > Also looking for a proper grid collet for the thing...
>> > Eimac 720359 ... anybody know a source? The grid collet
>> > may be my problem, but I am on my second "hamstyle" version and
>> > getting frustrated.
>> >
>> > The 2M version of the thing worked first try....
>> >
>> > Thanks..
>> >
>> > de K8RYU
>> > _______________________________________________
>> > VHFcontesting mailing list
>> > VHFcontesting@contesting.com
>> > http://lists.contesting.com/mailman/listinfo/vhfcontesting
>>
>> _______________________________________________
>> VHFcontesting mailing list
>> VHFcontesting@contesting.com
>> http://lists.contesting.com/mailman/listinfo/vhfcontesting
>>
>> _______________________________________________
>> VHFcontesting mailing list
>> VHFcontesting@contesting.com
>> http://lists.contesting.com/mailman/listinfo/vhfcontesting
>
> _______________________________________________
> VHFcontesting mailing list
> VHFcontesting@contesting.com
> http://lists.contesting.com/mailman/listinfo/vhfcontesting
------------------------------
Message: 5
Date: Wed, 21 Oct 2015 01:56:19 -0400
From: David Pruett <k8cc@comcast.net>
To: vhfcontesting@contesting.com
Subject: Re: [VHFcontesting] 3cx800a 222 amp
Message-ID: <56272903.8060307@comcast.net>
Content-Type: text/plain; charset=windows-1252; format=flowed
The details for removing the grid collet fingers are shown in the ARRL
UHF/Microwave Projects Manual, Volume 1 for the K1FO single and dual
tube 432 MHz 3CX800 amps, and the 432 MHz 8938 amp. Not sure how this
would relate to K8RYU's original question in a 222 MHz application, but
at least the illustrations clearly show the grid fingers and describe
how to break these off.
73, Dave/K8CC
On 10/20/2015 4:37 PM, Dave Olean wrote:
>
> Hi Bill et al.
> The one I remember was the grid collet for the 8938 on 432. It needed
> a slight bit of inductance for best neutralization. I remember that
> Steve figured it out, although the amplifier worked fine without it,
> you would see some drifting in the power output, no doubt due to some
> regeneration in the grid crcuit. After removing a small number of
> fingers from the grounded collet, the amplifier was much more stable
> as far as power output went. When I got the tube initially, W6PO
> indicated that it had flunked the stable power output test and was
> rejected for an order to the Swiss gov't. The tubes were for remote
> unattended sites where the tubes would normally be off until required
> and then had to reach full power from a cold start. Bob indicated that
> with use the tube would probably improve and be just fine. I did see
> power drift, which improved, but, by removing teeth from the finger
> stock, it got really stable. Now I do not notice much drift at all. I
> think Steve removed every fourth finger. I could always take the 432
> KW apart and look at the grid ring!
>
> Dave K1WHS
>
> ----- Original Message ----- From: "Bill Olson" <callbill@hotmail.com>
> To: "terry price" <w8zn54@verizon.net>; "VHF Contest Reflector"
> <vhfcontesting@contesting.com>
> Sent: Tuesday, October 20, 2015 4:48 PM
> Subject: Re: [VHFcontesting] 3cx800a 222 amp
>
>
>> yeah, duh, I was talking about the grid collet!! so where I said
>> "cathode connection" was just me being stupid, what I MEANT was I
>> seem to remember there needed to be just a little inductance in the
>> grid connection, so with homebrew collets you had to diddle with the
>> number of fingers a little..
>>
>> bill
>>
>>
>>
>>> From: w8zn54@verizon.net
>>> To: callbill@hotmail.com; vhfcontesting@contesting.com
>>> Date: Tue, 20 Oct 2015 12:39:16 -0400
>>> Subject: Re: [VHFcontesting] 3cx800a 222 amp
>>>
>>> I've built several 3CX800A7 222 amps and the cathode circuit that
>>> was used
>>> on the 8874 version was the same. The plate line changed.
>>>
>>> Terry - W8ZN
>>>
>>> -----Original Message-----
>>> From: VHFcontesting [mailto:vhfcontesting-bounces@contesting.com] On
>>> Behalf
>>> Of Bill Olson
>>> Sent: Tuesday, October 20, 2015 12:00 PM
>>> To: VHF Contest Reflector
>>> Subject: Re: [VHFcontesting] 3cx800a 222 amp
>>>
>>> Ralph, I'm really straining my brain here, but I seem to remember these
>>> triodes wanted a little inductance in the cathode connection to
>>> "neutralize"
>>> them. I remember with an 8874 on 220 back 35 or 40 years ago I build
>>> a home
>>> made grid collet with finger stock.. The finger stock was in a solid
>>> ring at
>>> first but in order to make the thing work I had to keep bending
>>> fingers away
>>> from the grid ring on the tube.. That's all I remember, don't have
>>> that amp
>>> any more..
>>>
>>> Steve, W1SMS, now owns and runs Lunar Link, I'm sure he has the info
>>> you
>>> want..
>>>
>>> bill, k1DY
>>>
>>> > Date: Tue, 20 Oct 2015 11:23:01 -0400
>>> > From: mathenyr@marietta.edu
>>> > To: vhfcontesting@contesting.com
>>> > Subject: [VHFcontesting] 3cx800a 222 amp
>>> >
>>> >
>>> >
>>> > I remember reading that there was a K1FO 222 amp using a single
>>> > 3xc800a7 tube. I have tired to get such an amp to behave without
>>> > success...cathode circuit problems.
>>> >
>>> > Does anyone know if the K1FO amp description was ever published?
>>> Does
>>> > anybody have one of the amps who could send me a copy of a manual or
>>> > perhaps photos??
>>> >
>>> > Also looking for a proper grid collet for the thing...
>>> > Eimac 720359 ... anybody know a source? The grid collet
>>> > may be my problem, but I am on my second "hamstyle" version and
>>> > getting frustrated.
>>> >
>>> > The 2M version of the thing worked first try....
>>> >
>>> > Thanks..
>>> >
>>> > de K8RYU
>>> > _______________________________________________
>>> > VHFcontesting mailing list
>>> > VHFcontesting@contesting.com
>>> > http://lists.contesting.com/mailman/listinfo/vhfcontesting
>>>
>>> _______________________________________________
>>> VHFcontesting mailing list
>>> VHFcontesting@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/vhfcontesting
>>>
>>> _______________________________________________
>>> VHFcontesting mailing list
>>> VHFcontesting@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/vhfcontesting
>>
>> _______________________________________________
>> VHFcontesting mailing list
>> VHFcontesting@contesting.com
>> http://lists.contesting.com/mailman/listinfo/vhfcontesting
>
> _______________________________________________
> VHFcontesting mailing list
> VHFcontesting@contesting.com
> http://lists.contesting.com/mailman/listinfo/vhfcontesting
>
>
------------------------------
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------------------------------
End of VHFcontesting Digest, Vol 154, Issue 8
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