[ARC5] Receiver drift tests
Paddy Ryan
pei7cn at eircom.net
Sun Nov 29 08:20:52 EST 2015
Thanks for the drift tests..pretty good..I do think the 303 is pretty stable
..the R4C here is not as good as that..the 101A should be interesting in due
course..73 de Pat/EI7CN
-----Original Message-----
From: arc5-request at mailman.qth.net
Sent: Sunday, November 29, 2015 5:09 AM
To: arc5 at mailman.qth.net
Subject: ARC5 Digest, Vol 142, Issue 108
Send ARC5 mailing list submissions to
arc5 at mailman.qth.net
To subscribe or unsubscribe via the World Wide Web, visit
http://mailman.qth.net/mailman/listinfo/arc5
or, via email, send a message with subject or body 'help' to
arc5-request at mailman.qth.net
You can reach the person managing the list at
arc5-owner at mailman.qth.net
When replying, please edit your Subject line so it is more specific
than "Re: Contents of ARC5 digest..."
Today's Topics:
1. Re: ART-13 Power Output (Leslie Smith)
2. Potential Good Deal (Robert Eleazer)
3. Fwd: Potential Good Deal (Rich Post)
4. Re: Potential Good Deal (Kenneth G. Gordon)
5. Re: Potential Good Deal (Bill Cromwell)
6. First Receiver Drift Test from KE6F (millerke6f at aol.com)
----------------------------------------------------------------------
Message: 1
Date: Fri, 27 Nov 2015 09:45:19 +1100
From: Leslie Smith <vk2bcu at operamail.com>
To: arc5 at mailman.qth.net
Subject: Re: [ARC5] ART-13 Power Output
Message-ID:
<1448577919.2487408.451075953.6C386136 at webmail.messagingengine.com>
Content-Type: text/plain
Hello Jeep,
All this proves that Richard Feynman was correct on two points.
First, it's necessary to "do the experiment", and after that to
understand that "nature cannot be fooled".
I like to hear the experience of others, because it broadens my
understanding.
Now I'm less confident about the idea of running (receiver) filaments
5% under-voltage.
I found supporting evidence for this in a (very old) technical book I
once saw.
According to that source, dropping the filament voltage to an
incandescent light would double the life of the globe - but give less
light out. Since the eye was logarithmic (in response) the decrease
in apparent brightness was less of a problem that the benefit of
longer tube life. Putting this in the context of a recent memory of
depression and the uncertainty of when WWII might end, I can
understand why the ARRL published this info.
73 de Les Smith
vk2bcu at operamail.com
On Fri, Nov 27, 2015, at 01:13, DSP3 wrote:
> Les,
>
> Well, you're arguably correct on all fronts. I elected to simply boost
> the a.c. input to the entire power supply, the results noted in the
> original post. I then split out the DC filament supply and ran it up to
> 28v. The power did come up to about 60% of the previous increase. What
> also did occur, however, was that the drive level was now up in the
> normal area. So, looks like they all have a factor. I do believe that
> my filament voltage may have been lower that I thought... maybe as low
> as 25v? That would account for the noteworthy increase. In that I use
> the ART-13s only a couple of hours a week, at most, running a
> conservative voltage probably won't do much for me. I do set the
> voltage on the 3-500Zs in the amplifiers I use at 5% less and limit the
> inrush. I appreciated your comments....
>
> Jeep - K3HVG
>
>
>
> On 11/25/2015 5:29 PM, Leslie Smith wrote:
> > G'day Jeep!
> > Recently I was asked to look at a non-functioning piece of laboratory
> > equipment - Bragg's Apparatus.
> > The key point of failure was the x-ray generator tube. I forget the
> > detail of the tube, but from memory the filament circuit had been
> > faulty. A fellow I know, Ken, had re-built the filament supply, and
> > from memory set the filament current, using a current regulator circuit
> > to deliver the current - to spec. Ken is a precise fellow and set the
> > current "right on spec" - if such a thing is possible. If my memory is
> > good "spec" was 1.25A, but my memory may be faulty on that point.
> >
> > No problem could be found. Everything was as it should be. A second
> > tube did nothing. Then I wound the current "up" ever so-slightly over
> > 1.25A. Bingo! Mr. Bragg was measuring x-ray diffraction again. I
> > was surprised that such a small (over-spec) adjustment of filament
> > current make the difference between nothing and working as expected.
> >
> > Now, an x-ray tube is quite different from the tubes in your set up.
> > Also, I remember that 'tubes' running with -5% filament voltage lasted a
> > LOT longer. (My recollection is that this was in the ARRL hand-book,
> > certainly early WWII. As a kid, I thought this was very important and
> > even calculated the value of a resistor that would do this
> > "preservation" for me.) So I and both surprised and not surprised by
> > your observation.
> >
> > I make one further observation. The B+ supply increased by a factor of
> > 1.15 and power is related to the square of the voltage. 1.15^2 x 110 ->
> > 145, and that's not too far below your measured 150W (probably within
> > the limit of error of your power meter etc). It may be that you have
> > measured an increase in power due to increased B+ supply. That's
> > another point of view.
> >
> > 73 de Les
> > vk2bcu at operamail.com
> > (end)
> >
> > On Thu, Nov 26, 2015, at 08:30, DSP3 wrote:
> >> Not to re-open a closed discussion but I noticed that one (probably
> >> both) of my ARC-8 setups had apparently dropped in power output. The
> >> p.s. for this system has the filament voltage at about 26.5 volts.
> >> With
> >> the line voltage down a bit as a function of increased neighborhood
> >> usage (assumed), the ART-13 was putting out about 110 watts. I noticed
> >> that the LV reading was down at the bottom of the arc, as was the
> >> drive. So, I put a 20A variac in the line and bumped the line voltage
> >> up so that I got 28v on the filaments. The low B+ came up from 380v to
> >> about 410v and the B+ from 1000v up to about 1150v. The power out is
> >> now back to an easy 150 watts, which I re-tuned back to a nominal 125
> >> watts. It would appear that filament voltage is more of a factor that
> >> I
> >> previously appreciated. As I mentioned earlier, I use about 700pf of
> >> loading on 75 meters. Anyway, as Chief Inspector Clouseau would say...
> >> "I have sol-ved the case".....
> >>
> >> Jeep - K3HVG
> >>
> >> ______________________________________________________________
> >> 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
>
> ______________________________________________________________
> 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
--
http://www.fastmail.com - Same, same, but different...
------------------------------
Message: 2
Date: Thu, 26 Nov 2015 18:11:38 -0500
From: "Robert Eleazer" <releazer at earthlink.net>
To: <arc5 at mailman.qth.net>
Subject: [ARC5] Potential Good Deal
Message-ID: <6B737C868078454A9DDC7D2A6BC887B7 at DH26DQ31>
Content-Type: text/plain; charset="iso-8859-1"
I just stumbled onto the fact that Amazon has " Goldsource STU-500 Step Up
and Down Voltage Converter Transformer, AC 110/220 V, 500 Watt" on sale for
$28.75. If you need a whole lot of 220V power from a 110V AC source it
sounds like a good deal.
Wayne
WB5WSV
------------------------------
Message: 3
Date: Fri, 27 Nov 2015 11:39:23 -0500
From: Rich Post <kb8tad at gmail.com>
To: ARC-5 List <arc5 at mailman.qth.net>
Subject: [ARC5] Fwd: Potential Good Deal
Message-ID:
<CAEJr0FuvrqyoD5K7m=YsMaqhk3h3VueGRRQ8EjMn66NL9f485w at mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
To: Robert Eleazer <releazer at earthlink.net>
These may be autotransformers. Most 120 - 240 volt transformers are. If
the primary and secondary windings are isolated then indeed, they are good
deals.
On Thu, Nov 26, 2015 at 6:11 PM, Robert Eleazer <releazer at earthlink.net>
wrote:
> I just stumbled onto the fact that Amazon has " Goldsource STU-500 Step Up
> and Down Voltage Converter Transformer, AC 110/220 V, 500 Watt" on sale
> for
> $28.75. If you need a whole lot of 220V power from a 110V AC source it
> sounds like a good deal.
>
> Wayne
> WB5WSV
> ______________________________________________________________
> 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
>
------------------------------
Message: 4
Date: Sat, 28 Nov 2015 09:55:05 -0800
From: "Kenneth G. Gordon" <kgordon2006 at frontier.com>
To: "Robert Eleazer" <releazer at earthlink.net>
Cc: ARC5 <arc5 at mailman.qth.net>
Subject: Re: [ARC5] Potential Good Deal
Message-ID: <5659EA79.2252.364A3E9F at kgordon2006.frontier.com>
Content-Type: text/plain; charset=US-ASCII
On 26 Nov 2015 at 18:11, Robert Eleazer wrote:
> I just stumbled onto the fact that Amazon has " Goldsource STU-500 Step Up
> and
> Down Voltage Converter Transformer, AC 110/220 V, 500 Watt" on sale for
> $28.75.
> If you need a whole lot of 220V power from a 110V AC source it sounds like
> a
> good deal.
Be careful: I bought something like that off eBay some time ago, mainly to
check it out. It is an auto-transformer, and is not a true isolation, or
"two
winding" transformer. I would be willing to bet that this "Goldsource" job
is
the same thing.
Ken W7EKB
------------------------------
Message: 5
Date: Sat, 28 Nov 2015 16:38:18 -0500
From: Bill Cromwell <wrcromwell at gmail.com>
To: arc5 at mailman.qth.net
Subject: Re: [ARC5] Potential Good Deal
Message-ID: <565A1ECA.9060400 at gmail.com>
Content-Type: text/plain; charset=windows-1252; format=flowed
Hi,
I didn't buy mine from eBay but from Mouser. I looked at the
schematic/wiring diagram and the unit shows two, separate windings and
when it arrived it indeed had two separate windings. I probably paid
more than I would have on the bay but often a company's performance and
reputation are worth something.
73,
Bill KU8H
On 11/28/2015 12:55 PM, Kenneth G. Gordon wrote:
> On 26 Nov 2015 at 18:11, Robert Eleazer wrote:
>
>> I just stumbled onto the fact that Amazon has " Goldsource STU-500 Step
>> Up and
>> Down Voltage Converter Transformer, AC 110/220 V, 500 Watt" on sale for
>> $28.75.
>> If you need a whole lot of 220V power from a 110V AC source it sounds
>> like a
>> good deal.
> Be careful: I bought something like that off eBay some time ago, mainly to
> check it out. It is an auto-transformer, and is not a true isolation, or
> "two
> winding" transformer. I would be willing to bet that this "Goldsource" job
> is
> the same thing.
>
> Ken W7EKB
>
------------------------------
Message: 6
Date: Sun, 29 Nov 2015 00:08:53 -0500
From: millerke6f at aol.com
To: arc5 at mailman.qth.net
Subject: [ARC5] First Receiver Drift Test from KE6F
Message-ID: <15151a4cd78-112e-ac48 at webprd-m55.mail.aol.com>
Content-Type: text/plain; charset=utf-8
Hi to those folks interested in the drift performance of the old Tube
Receiver. I found it too much of a task to run a bunch of receivers on a
concurrent drift test so will be running these one at a time under the same
controls I stipulated in my earlier postings
1. The ambient temperature in the shop during these tests was 62 degrees F.
2. The signal source Was an Agilent E4400B with an ovenized clock and
calibrated against my Rubidiium standard
3. Before any tests were made the receiver was allowed to warm up for 5
minutes at which time the 80 meter
test was made; RECEIVER was National NC-303 BFO on widest bandwidth 500 uV
from signal generator. Subsequent
bands were tested at nominal 1 hour intervals.
4. 80 Meters 3.7 MHz zero beat at 3:30 pm All drift numbers are from the
3.7 MHz reference point
3:35 pm drift +80 Hz (80 Hz change)
4:05 pm drift +81 Hz (1 Hz change)
4:15 pm drift +86 Hz (5 Hz change)
4:30 pm drift +91 Hz (5 Hz change)
5. 40 Meters 7.150 MH zero beat at 4:31 pm All drift numbers from the 7.150
Reference point
4:55 pm drift 15 Hz (15 Hz change)
5:01 pm drift 28 Hz (11 Hz change)
5:30 pm drift 00 Hz (28 Hz change back to zero beat)
6 20 Meters 14.2 MHz zero beat at 5:32 pm All drift numbers from the 14.2
MHz reference point
5:55 pm drift 84 Hz (84 Hz change)
6:30 pm drift 128 Hz (44 Hz change)
7, 15 Meters 21.250 MHz zero beat at 6:32 pm All drift numbers from the
21.250 MHz reference point
6:45 pm drift 20 hz (20 Hz change)
7:00 pm drift 41 Hz (21 Hz change)
7:15 pm drift 50 Hz (9 Hz change)
7:32 pm drift 61 Hz (11 Hz change)
8: 10 Meters 28.80 MHz zero beat at 7:35 pm all drift numbers from 28.8 MHz
reference point
8:00 pm drift 420 Hz (420 Hz change)
8:33 pm drift 590 Hz (170 Hz change)
It would appear that this receiver demonstrated fairly decent stability on
all but the 10 meter band and had that test been allowed to continue the 10
meter band would also have been usable as the rate of change was calming
down in the last 30 minutes. Overall mechanical stability is above average
but no drop tests were made at this time. The receiver is in average
condition and has been in dry storage for a few years. No modifications or
other work has been done on the unit. It even has the original filament
ballast tube in place.
Once i get the SX101A up on the bench I will run the same series on that
item. Comments invited on the procedures and results
73 Bob
------------------------------
Subject: Digest Footer
_______________________________________________
ARC5 mailing list
ARC5 at mailman.qth.net
http://mailman.qth.net/mailman/listinfo/arc5
------------------------------
End of ARC5 Digest, Vol 142, Issue 108
**************************************
More information about the ARC5
mailing list