[Hallicrafters] Black Beauty capacitors Beware
Jim Liles
hallicrafterssr2000 at k9axn.com
Sun Mar 8 14:07:28 EDT 2015
Hi Dave,
I sent a response with attached photos of a sweep of an SX-117 but it
failed. So I resent the narrative and will add the photos to the K9AXN web
site.
First off Dave, I don’t see anything in the mix that will reach down to
50Kc. Help me out on that one. Haven’t used that gear for years and years.
I don't see anything in the mix that can do a sweep except maybe the 8443A
and 141T but I don’t think they make it down to 50Kc.
I believe the output of the tracking generator is a bit high for the
I.F.Sweep so will probably need an attenuator. You need to get down to the
millivolt levels for I.F. and microvolt levels for the front end sweeps.
What is its minimum output.
Been a long time since I used a 141T but as I recall it has a storage CRT
standard. Does the storage function in your 141 work and are you familiar
with its use? If the storage function works, you can do a single manual
sweep by simply turning the frequency knob on the SG letting the 141 store
the trace.
I have to admit I’ve never used a tracking generator, never needed to do so.
Most Spectrum analyzers have storage CRT or max hold functions. What’s the
difference? About 30 seconds of your time and you can inject a precision
signal of any amplitude, composition, or purity.
Let us know if the storage function works and if you’re familiar with it’s
use.
The attached photos are of the SX-117 band pass .5Kc and 2.5Kc settings.
The 2.5Kc wave form looks to be only slightly wider than the .5Kc because we
doubled the sweep rate compressing the image. We used an HP 3325A which
uses a TTL transition for a matker. The down transition is the 50Kc point.
The .5Kc trace is 250 cycles per graticule and the 2.5Kc trace is .5Kc per
graticule.
Kindest regards Jim K9AXN
-----Original Message-----
From: David C. Hallam
Sent: Sunday, March 08, 2015 8:38 AM
To: Jim Liles ; hallicrafters at mailman.qth.net
Subject: Re: [Hallicrafters] Black Beauty capacitors Beware
Jim,
TEK 465 scope
HP 606B/8708A SG
HP 410C vtvm
HP 141T/8552B/8553B SA
HP 8443A tracking generator
HP 5246L FC
I also have an old EICO 369 sweep generator but I am not sure it is
working properly.
David
On 3/7/2015 10:06 PM, Jim Liles wrote:
> Dave,
> Tell us what equipment that you have available and we'll see what we can
> do to configure it to make it happen. Have you done any sweep analysis?
> Kindest regards Jim K9AXN
> -----Original Message-----
> From: David C. Hallam
> Sent: Saturday, March 07, 2015 4:01 PM
> To: hallicrafters at mailman.qth.net
> Subject: Re: [Hallicrafters] Black Beauty capacitors Beware
> Jim,
> What is the recommend procedure to sweep the the filter? I do not have
> a sweep generator but do have a good assortment of test equipment.
> David
> KW4DH
> On 3/7/2015 10:20 AM, Jim Liles wrote:
> > Hi Greg,
> > good assoermentr
> > Exactly! They were as good as film and legions better than
> ceramic. That’s why you still see paper defined on the schematics not
> ceramic caps.
> >
> > I still would replace the paper because as they dry out or begin to
> leak the Q goes to the devil. Won’t effect the .5Kc position because it
> doesn’t use them but when you use the higher band widths, especially the
> 1Kc, they will widen because of the denigration of the Q. May not be
> obvious but if you sweep that filter system it’s obvious. The band center
> skew jumps out at you when using the ceramic caps.
> >
> > In any case the paper at their worst will out perform ceramic unless
> they are shorted or open.
> >
> > One measure is, you should be able to tune in an SSB signal in the
> 5Kc position and dial right down through 1Kc and still clearly copy that
> conversation without touching the BFO and tuning to peak for clarity. The
> best definition that describes what you have to do when incorrect caps are
> installed is “You have to be a human I.F. shift mechanism” You have to
> tune an SSB signal then tune slightly back and fourth for peak strength
> while adjusting the BFO for clarity. You don’t want to go there, let the
> radio do it for you.
> >
> > One thing that I didn’t mention is the 390 ohm resistor will be well
> above 420 ohms. Those resistors are very critical. Get it right on or 5%
> below not above or the 5Kc position will droop excessively.
> >
> > Kindest regards Jim K9AXN
> >
> >
> >
> >
> >
> >
> >
> >
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2015.0.5751 / Virus Database: 4299/9248 - Release Date:
> 03/07/15
> --
> There are two possible outcomes: if the result confirms the hypothesis,
> then you've made a measurement.
> If the result is contrary to the hypothesis, then you've made a discovery.
> Enrico Fermi
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2015.0.5751 / Virus Database: 4299/9248 - Release Date: 03/07/15
> ______________________________________________________________
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>
> No virus found in this message.
> Checked by AVG - www.avg.com <http://www.avg.com>
> Version: 2015.0.5751 / Virus Database: 4299/9248 - Release Date: 03/07/15
>
--
There are two possible outcomes: if the result confirms the hypothesis, then
you've made a measurement.
If the result is contrary to the hypothesis, then you've made a discovery.
Enrico Fermi
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.5751 / Virus Database: 4299/9253 - Release Date: 03/08/15
______________________________________________________________
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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Hallicrafters at mailman.qth.net
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-----Original Message-----
From: David C. Hallam
Sent: Sunday, March 08, 2015 8:38 AM
To: Jim Liles ; hallicrafters at mailman.qth.net
Subject: Re: [Hallicrafters] Black Beauty capacitors Beware
Jim,
TEK 465 scope
HP 606B/8708A SG
HP 410C vtvm
HP 141T/8552B/8553B SA
HP 8443A tracking generator
HP 5246L FC
I also have an old EICO 369 sweep generator but I am not sure it is
working properly.
David
On 3/7/2015 10:06 PM, Jim Liles wrote:
> Dave,
> Tell us what equipment that you have available and we'll see what we can
> do to configure it to make it happen. Have you done any sweep analysis?
> Kindest regards Jim K9AXN
> -----Original Message-----
> From: David C. Hallam
> Sent: Saturday, March 07, 2015 4:01 PM
> To: hallicrafters at mailman.qth.net
> Subject: Re: [Hallicrafters] Black Beauty capacitors Beware
> Jim,
> What is the recommend procedure to sweep the the filter? I do not have
> a sweep generator but do have a good assortment of test equipment.
> David
> KW4DH
> On 3/7/2015 10:20 AM, Jim Liles wrote:
> > Hi Greg,
> > good assoermentr
> > Exactly! They were as good as film and legions better than
> ceramic. That’s why you still see paper defined on the schematics not
> ceramic caps.
> >
> > I still would replace the paper because as they dry out or begin to
> leak the Q goes to the devil. Won’t effect the .5Kc position because it
> doesn’t use them but when you use the higher band widths, especially the
> 1Kc, they will widen because of the denigration of the Q. May not be
> obvious but if you sweep that filter system it’s obvious. The band center
> skew jumps out at you when using the ceramic caps.
> >
> > In any case the paper at their worst will out perform ceramic unless
> they are shorted or open.
> >
> > One measure is, you should be able to tune in an SSB signal in the
> 5Kc position and dial right down through 1Kc and still clearly copy that
> conversation without touching the BFO and tuning to peak for clarity. The
> best definition that describes what you have to do when incorrect caps are
> installed is “You have to be a human I.F. shift mechanism” You have to
> tune an SSB signal then tune slightly back and fourth for peak strength
> while adjusting the BFO for clarity. You don’t want to go there, let the
> radio do it for you.
> >
> > One thing that I didn’t mention is the 390 ohm resistor will be well
> above 420 ohms. Those resistors are very critical. Get it right on or 5%
> below not above or the 5Kc position will droop excessively.
> >
> > Kindest regards Jim K9AXN
> >
> >
> >
> >
> >
> >
> >
> >
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2015.0.5751 / Virus Database: 4299/9248 - Release Date:
> 03/07/15
> --
> There are two possible outcomes: if the result confirms the hypothesis,
> then you've made a measurement.
> If the result is contrary to the hypothesis, then you've made a discovery.
> Enrico Fermi
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2015.0.5751 / Virus Database: 4299/9248 - Release Date: 03/07/15
> ______________________________________________________________
> Hallicrafters mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hallicrafters
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Hallicrafters at mailman.qth.net
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer at usol.com **
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
> No virus found in this message.
> Checked by AVG - www.avg.com <http://www.avg.com>
> Version: 2015.0.5751 / Virus Database: 4299/9248 - Release Date: 03/07/15
>
--
There are two possible outcomes: if the result confirms the hypothesis, then
you've made a measurement.
If the result is contrary to the hypothesis, then you've made a discovery.
Enrico Fermi
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.5751 / Virus Database: 4299/9253 - Release Date: 03/08/15
______________________________________________________________
Hallicrafters mailing list
Home: http://mailman.qth.net/mailman/listinfo/hallicrafters
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Hallicrafters at mailman.qth.net
List Administrator: Duane Fischer, W8DBF
** For Assistance: dfischer at usol.com **
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
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