[ARC5] ARC5 Digest, Vol 142, Issue 38
Paddy Ryan
pei7cn at eircom.net
Sat Nov 14 09:32:08 EST 2015
My experience of the Hallicrafters:
SX-28 good stability..SX-25 fair..SX-101 very good..SX-62 very good..SX-117
excellent (as good as the 75S-1)..S85 poor..S40A poor..on the ARC-5 tx vfo I
have a T18 and it seems very stable and drifts less than a kHz in an hour
and never moves at all after that (in unloaded condition)..the Halli's look
beautiful though!..73 de Pat/EI7CN
-----Original Message-----
From: arc5-request at mailman.qth.net
Sent: Friday, November 13, 2015 8:28 PM
To: arc5 at mailman.qth.net
Subject: ARC5 Digest, Vol 142, Issue 38
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Today's Topics:
1. Re: ARC-5 as VFO (Kenneth G. Gordon)
2. Re: ARC-5 as VFO (Kenneth G. Gordon)
3. Re: ARC-5 as VFO (mstangelo at comcast.net)
4. Re: ARC-5 as VFO (Kenneth G. Gordon)
5. Re: ARC-5 as VFO (kn7sfz)
6. Re: [Milsurplus] B-10 Exported with SCR-134, SCR-183
(Gordon White)
7. Re: ARC-5 as VFO (Phillip Carpenter)
----------------------------------------------------------------------
Message: 1
Date: Fri, 13 Nov 2015 08:24:23 -0800
From: "Kenneth G. Gordon" <kgordon2006 at frontier.com>
To: WA5CAB--- via ARC5 <arc5 at mailman.qth.net>
Subject: Re: [ARC5] ARC-5 as VFO
Message-ID: <56460EB7.13398.19118A at kgordon2006.frontier.com>
Content-Type: text/plain; charset=US-ASCII
On 13 Nov 2015 at 1:02, WA5CAB--- via ARC5 wrote:
> There are a total of four variable capacitors in a Command Set transmitter
> (whether ATA, SCR-274-N or AN/ARC-5). I would assume that Ken meant the
> PA
> Tuning and Padder capacitors.
Yes. Vs the MO tuning cap.
> The only difference that I can see between those
> two and the MO tuning one are the frames.
Well, the MO tuning cap ALSO has a much better vernier.
I learned some of this from a recent article in Electric Radio Magazine by
an
author who made an excellent SSB rig out of a derelict ARC-5 transmitter. It
was a two (or maybe even three) part article.
For his VFO, he tried one of the transmitter tuning or padder caps, but
found
them wanting, then switched to the MO tuning cap, which solved his drift and
tuning problems.
I have never seen anything "official" about the possible differences between
the tuning/padding caps and the MO cap, but to me it would make sense that
the MO cap would be the highest possible quality.
It might also help to explain why the transmitters are so unusually stable.
I
have always wondered why the temperature compensating cap in the ARC-5
VFOs was so small. Usually, those have to be both greater in capacitance
and have a far higher temp-co.
Perhaps someone with better test equipment than I have could devote some
time to examining the cap a bit more closely?
Ken W7EKB
------------------------------
Message: 2
Date: Fri, 13 Nov 2015 08:54:23 -0800
From: "Kenneth G. Gordon" <kgordon2006 at frontier.com>
To: Arc5 at mailman.qth.net
Subject: Re: [ARC5] ARC-5 as VFO
Message-ID: <564615BF.31808.348BA9 at kgordon2006.frontier.com>
Content-Type: text/plain; charset=US-ASCII
On 13 Nov 2015 at 14:31, AKLDGUY . wrote:
> That may be a bit unfair to Hallicrafters.
Well....no....
MOST of the early Hallicrafters receivers were notoriously unstable. I was
amazed, since their transmitters were so stable.
The SX-28 was stable, but then Halli dropped the ball on receiver stability
until their later receivers, when they became stable again.
The SX-100 was horrible that way. Both mechanically and electronically
unstable. Tapping on the table was very obvious.
> In 1983, I bought a deceased estate SR-150 transceiver of 1963 vintage
> via a workmate and worked the world with it on 20m SSB with a dipole.
Yes, that was the era when stability returned to Halli rigs. The SX-101 and
the SX-115, and SX-117 were good. Other cheaper receivers were terrible.
I am speaking from experience...
Ken W7EKB
------------------------------
Message: 3
Date: Fri, 13 Nov 2015 18:36:37 +0000 (UTC)
From: mstangelo at comcast.net
To: Ken Gordon <kgordon2006 at frontier.com>
Cc: Arc5 at mailman.qth.net
Subject: Re: [ARC5] ARC-5 as VFO
Message-ID:
<457426566.596458.1447439797104.JavaMail.zimbra at comcast.net>
Content-Type: text/plain; charset=utf-8
There was an article in Ham Radio magazine discussing the stability of the
variable capacitors used in Command Set transmitters.
It did mention the tpye of metal used in the construction; I don't remember
if it referred to the MO capacitor or all of the variables used in the set.
I'll have to dig out that article.
Mike N2MS
----- Original Message -----
From: Kenneth G. Gordon <kgordon2006 at frontier.com>
To: Arc5 at mailman.qth.net
Sent: Fri, 13 Nov 2015 00:45:04 -0000 (UTC)
Subject: Re: [ARC5] ARC-5 as VFO
On 12 Nov 2015 at 18:20, David Stinson wrote:
<snip>
BTW, it is my understanding that the VFO capacitor in the ARC-5 transmitter
is a
considerably higher-quality model than either of the other two tuning caps
in the
transmitters.
The VFO cap plates are supposed to be made of something like Invar so it is
inherently
temperature compensating.
<snip>
Ken W7EKB
______________________________________________________________
------------------------------
Message: 4
Date: Fri, 13 Nov 2015 11:13:02 -0800
From: "Kenneth G. Gordon" <kgordon2006 at frontier.com>
To: Arc5 at mailman.qth.net
Subject: Re: [ARC5] ARC-5 as VFO
Message-ID: <5646363E.26247.B3798E at kgordon2006.frontier.com>
Content-Type: text/plain; charset=US-ASCII
On 13 Nov 2015 at 18:36, mstangelo at comcast.net wrote:
> There was an article in Ham Radio magazine discussing the stability of the
> variable capacitors used in Command Set transmitters.
>
> It did mention the tpye of metal used in the construction; I don't
> remember if
> it referred to the MO capacitor or all of the variables used in the set.
>
> I'll have to dig out that article.
Boy! Would I ever love to see that!
Ken W7EKB
------------------------------
Message: 5
Date: Fri, 13 Nov 2015 11:35:32 -0800
From: kn7sfz <kn7sfz at gmail.com>
To: arc5 at mailman.qth.net
Subject: Re: [ARC5] ARC-5 as VFO
Message-ID: <56463B84.8090705 at gmail.com>
Content-Type: text/plain; charset=windows-1252; format=flowed
Nothing jumped out at me in the Ham Radio index page:
http://webhome.idirect.com/~griffith/hrindex.htm#index
Richard kn7sfz
On 11/13/2015 11:13, Kenneth G. Gordon wrote:
> On 13 Nov 2015 at 18:36, mstangelo at comcast.net wrote:
>
>> There was an article in Ham Radio magazine discussing the stability of
>> the
>> variable capacitors used in Command Set transmitters.
>>
>> It did mention the tpye of metal used in the construction; I don't
>> remember if
>> it referred to the MO capacitor or all of the variables used in the set.
>>
>> I'll have to dig out that article.
> Boy! Would I ever love to see that!
>
> Ken W7EKB
> ______________________________________________________________
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------------------------------
Message: 6
Date: Fri, 13 Nov 2015 15:31:50 -0500
From: Gordon White <gewhite at crosslink.net>
To: arc5 at mailman.qth.net
Subject: Re: [ARC5] [Milsurplus] B-10 Exported with SCR-134, SCR-183
Message-ID: <564648B6.7090908 at crosslink.net>
Content-Type: text/plain; charset=windows-1252; format=flowed
I may be able to get to the US Archives if I have specific questions.
- Gordon Eliot White
------------------------------
Message: 7
Date: Fri, 13 Nov 2015 15:28:47 -0500
From: Phillip Carpenter <carpenterpa at tds.net>
To: "kgordon2006 at frontier.com" <kgordon2006 at frontier.com>
Cc: "Arc5 at mailman.qth.net" <Arc5 at mailman.qth.net>
Subject: Re: [ARC5] ARC-5 as VFO
Message-ID: <A04738ED-0355-43B0-BD0D-CC870C52E43A at tds.net>
Content-Type: text/plain; charset=us-ascii
Ken,
Are you implying that all Hallicrafters receivers after the SX-28 and up to
the SX-101 are inherently unstable?
I agree regarding the S-38 but what about the S-40A, SX-42, SX-43, or even
the SX-73/R-274D FFR?
Phillip
Sent from my iPhone
> On Nov 13, 2015, at 11:54 AM, Kenneth G. Gordon <kgordon2006 at frontier.com>
> wrote:
>
>> On 13 Nov 2015 at 14:31, AKLDGUY . wrote:
>>
>> That may be a bit unfair to Hallicrafters.
>
> Well....no....
>
> MOST of the early Hallicrafters receivers were notoriously unstable. I was
> amazed, since their transmitters were so stable.
>
> The SX-28 was stable, but then Halli dropped the ball on receiver
> stability
> until their later receivers, when they became stable again.
>
> The SX-100 was horrible that way. Both mechanically and electronically
> unstable. Tapping on the table was very obvious.
>
>> In 1983, I bought a deceased estate SR-150 transceiver of 1963 vintage
>> via a workmate and worked the world with it on 20m SSB with a dipole.
>
> Yes, that was the era when stability returned to Halli rigs. The SX-101
> and
> the SX-115, and SX-117 were good. Other cheaper receivers were terrible.
>
> I am speaking from experience...
>
> Ken W7EKB
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
------------------------------
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