[R-390] R-390 Digest, Vol 220, Issue 6

Fri Oct 7 21:31:46 EDT 2022

I went looking for info on Selenium Rectifiers and came across this link,
fwiw.
https://www.antiqueradios.com/forums/viewtopic.php?t=305477

Includes a link to a Selenium Rectifier data book and a nice discussion
thread.  I've never done any modeling myself.
73 de N5CQU - JP

On Fri, Oct 7, 2022 at 4:31 PM <r-390-request at mailman.qth.net> wrote:

> Send R-390 mailing list submissions to
>         r-390 at mailman.qth.net
>
> To subscribe or unsubscribe via the World Wide Web, visit
>         http://mailman.qth.net/mailman/listinfo/r-390
> or, via email, send a message with subject or body 'help' to
>         r-390-request at mailman.qth.net
>
> You can reach the person managing the list at
>         r-390-owner at mailman.qth.net
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of R-390 digest..."
>
>
> Today's Topics:
>
>    1. Re: R-390 Antenna Relay Chatter (Barry)
>    2. Re: R-390 Antenna Relay Chatter (wc4g at knology.net)
>    3. Re: R-390 Antenna Relay Chatter (Jim Whartenby)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 7 Oct 2022 16:20:22 -0400 (EDT)
> From: Barry <n4buq at knology.net>
> To: Les Locklear <leslocklear at hotmail.com>
> Cc: R-390 Mailing List <r-390 at mailman.qth.net>
> Subject: Re: [R-390] R-390 Antenna Relay Chatter
> Message-ID:
>         <1547716659.12353022.1665174022431.JavaMail.zimbra at knology.net>
> Content-Type: text/plain; charset=utf-8
>
> Thanks, Les.  I'm currently "soft-starting" it with an autotransformer and
> setting it to 115VAC for final run voltage.  I plan to add the thermistor
> and possibly a bucking circuit as well.
>
> Thanks,
> Barry - N4BUQ
>
> ----- Original Message -----
> > From: "Les Locklear" <leslocklear at hotmail.com>
> > To: "Jordan Arndt" <Outposter30 at shaw.ca>, "n4buq" <n4buq at knology.net>
> > Cc: "R-390 Mailing List" <r-390 at mailman.qth.net>
> > Sent: Friday, October 7, 2022 3:13:04 PM
> > Subject: Re: [R-390] R-390 Antenna Relay Chatter
>
> > Like Jordan said...the voltages are pretty much the same. I would just
> replace
> > it. The few pieces of tube gear I own all have a thermistor and
> > am using a bucking transformer to provide 115 Volts AC.
> >
> > Les
> >
> >
> > ----- Original Message -----
> > From: Jordan Arndt <Outposter30 at shaw.ca>
> > To: Barry <n4buq at knology.net>, Les Locklear <leslocklear at hotmail.com>
> > Cc: R-390 Mailing List <r-390 at mailman.qth.net>
> > Sent: 10/7/2022 2:39:55 PM
> > Subject: Re: [R-390] R-390 Antenna Relay Chatter
> >
> ________________________________________________________________________________
> >
> >
> > I stopped using "Stand By" on all my tube gear because the manner in
> which
> > it is usually implemented allows the B+ voltages to soar, often beyond
> the
> > rated voltages of caps and any other components exposed to the unloaded
> B+
> > voltage.
> >
> > I also add a CL-90 thermistor in the AC line on all the tube gear I'd
> like
> > to keep running. It drops the input AC by a few volts and provides an
> > automatic soft-start. Just make sure there is some air circulation around
> > the thermistor and that it's not too close to wiring and other heat
> > sensitive parts, because they do give quite a bit of heat.
> >
> > The 390 and 390A antenna relay circuit is pretty much the same, aside
> from
> > the voltage IIRC, so the rectifier issues are also pretty much the same.
> >
> > It sounds to me like your rectifier is in the process of failing. What
> > happens when you use the Break In circuit...?  Does it chatter when
> > operating in Break In mode also..?
> >
> > 73...Jordan VE6ZT
> >
> > ----- Original Message -----
> > From: "Barry" <n4buq at knology.net>
> > To: "Les Locklear" <leslocklear at hotmail.com>
> > Cc: "R-390 Mailing List" <r-390 at mailman.qth.net>
> > Sent: Friday, October 07, 2022 1:08 PM
> > Subject: Re: [R-390] R-390 Antenna Relay Chatter
> >
> >
> >> Hi Les,
> >>
> >> That advice appears to pertain to an R390A. This is an R390. Do you
> think
> >> that would make any difference?
> >>
> >> BTW, I was using STANDBY primarily for warmup.
> >>
> >> Thanks,
> >> Barry - N4BUQ
> >>
> >>> From: "Les Locklear" <leslocklear at hotmail.com>
> >>> To: "David Wise" <d44617665 at hotmail.com>, "n4buq" <n4buq at knology.net>,
> >>> "R-390
> >>> Mailing List" <r-390 at mailman.qth.net>
> >>> Sent: Friday, October 7, 2022 12:33:17 PM
> >>> Subject: Re: R-390 Antenna Relay Chatter
> >>
> >>> From the "Archives"
> >>
> >>> DO NOT use the "STANDBY" position on the FUNCTION switch. The now
> >>> unloaded
> >>> stages will cause the various voltages in the receiver to rise upwards
> >>> perhaps
> >>> beyond the tolerances of some critical components. This is caused by
> the
> >>> multiplicity error in our sometimes 120v+ line voltage v/s the 115v in
> >>> use when
> >>> the 390A was designed and built. Since it is normal for the "LOCAL
> GAIN"
> >>> control to not completely mute the audio when turned down fully, it is
> >>> natural
> >>> to consider putting the receiver in "STANDBY." Remember, DON'T.
> Instead,
> >>> turn
> >>> the audio down and also back off the RF GAIN control to about 11
> o'clock
> >>> and
> >>> the residual audio will disappear and no damage will be done to the
> >>> receiver.
> >>
> >>> Les Locklear
> >>
> >>> From: r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net> on
> >>> behalf of
> >>> David Wise <d44617665 at hotmail.com>
> >>> Sent: Friday, October 7, 2022 12:12 PM
> >>> To: Barry <n4buq at knology.net>; R-390 Mailing List <
> r-390 at mailman.qth.net>
> >>> Subject: Re: [R-390] R-390 Antenna Relay Chatter
> >>> Should not chatter. #1 suspect is CR801; selenium rectifiers have a
> >>> notorious
> >>> habit of increasing forward resistance as they age. Convert to silicon
> >>> plus a
> >>> resistor in series to mimic the natural forward resistance of new
> >>> selenium. (I
> >>> don't know what that value should be.) This is what Tektronix did with
> >>> their
> >>> oscilloscopes; for every selenium-powered model, they created a silicon
> >>> retrofit kit. One of my scopes has one.
> >>
> >>> Or you can add a reservoir capacitor, starting small and increasing
> until
> >>> the
> >>> chatter is reliably gone at low mains voltage. I am using 100uF. Upside
> >>> is
> >>> potentially reduced hum. Downside is that CR801 will continue to
> >>> deteriorate,
> >>> so eventually the problem will recur.
> >>
> >>> HTH,
> >>> Dave Wise
> >>> SWL (inactive)
> >>> ________________________________
> >>> From: r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net> on
> >>> behalf of
> >>> Barry <n4buq at knology.net>
> >>> Sent: Friday, October 7, 2022 9:59 AM
> >>> To: R-390 Mailing List <r-390 at mailman.qth.net>
> >>> Subject: [R-390] R-390 Antenna Relay Chatter
> >>
> >>> When in STANDBY, the antenna relay in my R-390 produces a bit of
> chatter.
> >>> Is
> >>> this normal? I see where that relay is fed, unfiltered, from CR801
> which,
> >>> from
> >>> the pictures in the manual, appear to be a stack of selenium diodes and
> >>> I'm
> >>> wondering if that rectifier stack might be a problem. Anyone know what
> to
> >>> expect from that relay in STANDBY and, perhaps, what I'm seeing might
> be
> >>> normal?
> >>
> >>> Thanks,
> >>> Barry - N4BUQ
> >>> ______________________________________________________________
> >>> R-390 mailing list
> >>> Home: [ http://mailman.qth.net/mailman/listinfo/r-390 |
> >>> http://mailman.qth.net/mailman/listinfo/r-390 ]
> >>> Help: [ http://mailman.qth.net/mmfaq.htm |
> >>> http://mailman.qth.net/mmfaq.htm ]
> >>> Post: [ mailto:R-390 at mailman.qth.net | mailto:R-390 at mailman.qth.net ]
> >>
> >>> This list hosted by: [ http://www.qsl.net/ | http://www.qsl.net ]
> >>> Please help support this email list: [ http://www.qsl.net/donate.html
> |
> >>> http://www.qsl.net/donate.html ]
> >>> ______________________________________________________________
> >>> R-390 mailing list
> >>> Home: [ http://mailman.qth.net/mailman/listinfo/r-390 |
> >>> http://mailman.qth.net/mailman/listinfo/r-390 ]
> >>> Help: [ http://mailman.qth.net/mmfaq.htm |
> >>> http://mailman.qth.net/mmfaq.htm ]
> >>> Post: [ mailto:R-390 at mailman.qth.net | mailto:R-390 at mailman.qth.net ]
> >>
> >>> This list hosted by: [ http://www.qsl.net/ | http://www.qsl.net ]
> >>> Please help support this email list: [ http://www.qsl.net/donate.html
> |
> >>> http://www.qsl.net/donate.html ]
> >> ______________________________________________________________
> >> R-390 mailing list
> >> Home: http://mailman.qth.net/mailman/listinfo/r-390
> >> Help: http://mailman.qth.net/mmfaq.htm
> >> Post: mailto:R-390 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: 2
> Date: Fri, 7 Oct 2022 16:20:13 -0400
> From: "wc4g at knology.net" <donwc4g at gmail.com>
> To: Jordan Arndt <Outposter30 at shaw.ca>
> Cc: R-390 Mailing List <r-390 at mailman.qth.net>
> Subject: Re: [R-390] R-390 Antenna Relay Chatter
> Message-ID:
>         <
> CAFDxT7b8mdfyp6oQLf07pn9-uT2KdSW6XKooxgribQFXJ28NYA at mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
>
> I don't think the B+ will soar in an R-390 because the B+ is regulated. Not
> so in the "A" model. That is where I think this issue originated.
>
> The antenna relay is only energized in STBY, BRK IN or CAL. As soon as the
> FUNCTION switch is turned to STBY, the B+ comes up.
> The B+ will increase only if the regulator circuit develops a problem and
> regulation is lost. (R-390)
>
> All of my equipment "sees" ~117VAC due to my BIG bucking transformer.
>
> Regards,
> Don WC4G
>
>
> On Fri, Oct 7, 2022 at 3:40 PM Jordan Arndt <Outposter30 at shaw.ca> wrote:
>
> > I stopped using "Stand By" on all my tube gear because the manner in
> which
> > it is usually implemented allows the B+ voltages to soar, often beyond
> the
> > rated voltages of caps and any other components exposed to the unloaded
> B+
> > voltage.
> >
> > I also add a CL-90 thermistor in the AC line on all the tube gear I'd
> like
> > to keep running. It drops the input AC by a few volts and provides an
> > automatic soft-start. Just make sure there is some air circulation around
> > the thermistor and that it's not too close to wiring and other heat
> > sensitive parts, because they do give quite a bit of heat.
> >
> > The 390 and 390A antenna relay circuit is pretty much the same, aside
> from
> > the voltage IIRC, so the rectifier issues are also pretty much the same.
> >
> > It sounds to me like your rectifier is in the process of failing. What
> > happens when you use the Break In circuit...?  Does it chatter when
> > operating in Break In mode also..?
> >
> > 73...Jordan VE6ZT
> >
> > ----- Original Message -----
> > From: "Barry" <n4buq at knology.net>
> > To: "Les Locklear" <leslocklear at hotmail.com>
> > Cc: "R-390 Mailing List" <r-390 at mailman.qth.net>
> > Sent: Friday, October 07, 2022 1:08 PM
> > Subject: Re: [R-390] R-390 Antenna Relay Chatter
> >
> >
> > > Hi Les,
> > >
> > > That advice appears to pertain to an R390A. This is an R390. Do you
> > think
> > > that would make any difference?
> > >
> > > BTW, I was using STANDBY primarily for warmup.
> > >
> > > Thanks,
> > > Barry - N4BUQ
> > >
> > >> From: "Les Locklear" <leslocklear at hotmail.com>
> > >> To: "David Wise" <d44617665 at hotmail.com>, "n4buq" <n4buq at knology.net
> >,
> > >> "R-390
> > >> Mailing List" <r-390 at mailman.qth.net>
> > >> Sent: Friday, October 7, 2022 12:33:17 PM
> > >> Subject: Re: R-390 Antenna Relay Chatter
> > >
> > >> From the "Archives"
> > >
> > >> DO NOT use the "STANDBY" position on the FUNCTION switch. The now
> > >> unloaded
> > >> stages will cause the various voltages in the receiver to rise upwards
> > >> perhaps
> > >> beyond the tolerances of some critical components. This is caused by
> the
> > >> multiplicity error in our sometimes 120v+ line voltage v/s the 115v in
> > >> use when
> > >> the 390A was designed and built. Since it is normal for the "LOCAL
> GAIN"
> > >> control to not completely mute the audio when turned down fully, it is
> > >> natural
> > >> to consider putting the receiver in "STANDBY." Remember, DON'T.
> > Instead,
> > >> turn
> > >> the audio down and also back off the RF GAIN control to about 11
> > o'clock
> > >> and
> > >> the residual audio will disappear and no damage will be done to the
> > >> receiver.
> > >
> > >> Les Locklear
> > >
> > >> From: r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net>
> on
> > >> behalf of
> > >> David Wise <d44617665 at hotmail.com>
> > >> Sent: Friday, October 7, 2022 12:12 PM
> > >> To: Barry <n4buq at knology.net>; R-390 Mailing List <
> > r-390 at mailman.qth.net>
> > >> Subject: Re: [R-390] R-390 Antenna Relay Chatter
> > >> Should not chatter. #1 suspect is CR801; selenium rectifiers have a
> > >> notorious
> > >> habit of increasing forward resistance as they age. Convert to silicon
> > >> plus a
> > >> resistor in series to mimic the natural forward resistance of new
> > >> selenium. (I
> > >> don't know what that value should be.) This is what Tektronix did with
> > >> their
> > >> oscilloscopes; for every selenium-powered model, they created a
> silicon
> > >> retrofit kit. One of my scopes has one.
> > >
> > >> Or you can add a reservoir capacitor, starting small and increasing
> > until
> > >> the
> > >> chatter is reliably gone at low mains voltage. I am using 100uF.
> Upside
> > >> is
> > >> potentially reduced hum. Downside is that CR801 will continue to
> > >> deteriorate,
> > >> so eventually the problem will recur.
> > >
> > >> HTH,
> > >> Dave Wise
> > >> SWL (inactive)
> > >> ________________________________
> > >> From: r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net>
> on
> > >> behalf of
> > >> Barry <n4buq at knology.net>
> > >> Sent: Friday, October 7, 2022 9:59 AM
> > >> To: R-390 Mailing List <r-390 at mailman.qth.net>
> > >> Subject: [R-390] R-390 Antenna Relay Chatter
> > >
> > >> When in STANDBY, the antenna relay in my R-390 produces a bit of
> > chatter.
> > >> Is
> > >> this normal? I see where that relay is fed, unfiltered, from CR801
> > which,
> > >> from
> > >> the pictures in the manual, appear to be a stack of selenium diodes
> and
> > >> I'm
> > >> wondering if that rectifier stack might be a problem. Anyone know what
> > to
> > >> expect from that relay in STANDBY and, perhaps, what I'm seeing might
> be
> > >> normal?
> > >
> > >> Thanks,
> > >> Barry - N4BUQ
> > >> ______________________________________________________________
> > >> R-390 mailing list
> > >> Home: [ http://mailman.qth.net/mailman/listinfo/r-390 |
> > >> http://mailman.qth.net/mailman/listinfo/r-390 ]
> > >> Help: [ http://mailman.qth.net/mmfaq.htm |
> > >> http://mailman.qth.net/mmfaq.htm ]
> > >> Post: [ mailto:R-390 at mailman.qth.net | mailto:R-390 at mailman.qth.net ]
> > >
> > >> This list hosted by: [ http://www.qsl.net/ | http://www.qsl.net ]
> > >> Please help support this email list: [ http://www.qsl.net/donate.html
> |
> > >> http://www.qsl.net/donate.html ]
> > >> ______________________________________________________________
> > >> R-390 mailing list
> > >> Home: [ http://mailman.qth.net/mailman/listinfo/r-390 |
> > >> http://mailman.qth.net/mailman/listinfo/r-390 ]
> > >> Help: [ http://mailman.qth.net/mmfaq.htm |
> > >> http://mailman.qth.net/mmfaq.htm ]
> > >> Post: [ mailto:R-390 at mailman.qth.net | mailto:R-390 at mailman.qth.net ]
> > >
> > >> This list hosted by: [ http://www.qsl.net/ | http://www.qsl.net ]
> > >> Please help support this email list: [ http://www.qsl.net/donate.html
> |
> > >> http://www.qsl.net/donate.html ]
> > > ______________________________________________________________
> > > R-390 mailing list
> > > Home: http://mailman.qth.net/mailman/listinfo/r-390
> > > Help: http://mailman.qth.net/mmfaq.htm
> > > Post: mailto:R-390 at mailman.qth.net
> > >
> > > This list hosted by: http://www.qsl.net
> > > Please help support this email list: http://www.qsl.net/donate.html
> >
> > ______________________________________________________________
> > R-390 mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/r-390
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:R-390 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: 3
> Date: Fri, 7 Oct 2022 20:30:46 +0000 (UTC)
> From: Jim Whartenby <old_radio at aol.com>
> To: "r-390 at mailman.qth.net" <r-390 at mailman.qth.net>
> Subject: Re: [R-390] R-390 Antenna Relay Chatter
> Message-ID: <1025174038.6289156.1665174646231 at mail.yahoo.com>
> Content-Type: text/plain; charset="utf-8"
>
> Onewould have to assume that the Collins people who designed the R-390and
> the R390A knew what they were doing. True, the B+, like anyother voltage,
> will rise as the load is decreased. But I amconfident that this rise was
> accounted for in the original designs bycompetent engineers.
> Asfor AC line voltage increasing over the years, this is simply
> amisunderstanding of the line voltage conventions which started wayback in
> 1927 with the beginning of AC powered radios.
> Whenthe Edison Three Wire DC Distribution System was adopted for use
> withAC, there were two voltagechoices for AC powered devices in the home.
> In the very beginningthese voltages were either115vac or 230vac. Overtime,
> as demand for electric power grew, more distributiontransformers were added
> to the local distribution system whichreduced IR losses and this reduced
> line voltage fluctuations.
> 115vac,117vac and 120vac line voltages are just voltage standards, used
> todifferentiate between the two Edison inspired AC voltages availableto the
> home and not the actual line voltage present at the "socket."One cannot
> expect the AC line voltage to remain at a steady statevoltage throughout
> the day under the varying loads presented to thedistribution system.
> Theactual line voltages for the three standards are:115vac +/- 10% or
> 103vac to 127vac117vac +/- 7.5% or 108vac to 126vac120vac +/- 5% or 114vac
> to 126vac
> Thethree rating standards above are the result of surveys done in
> the1920's, 1940's and 1960's by either NEMA (National
> ElectricalManufacturers Association) or other groups that also included
> NEMA orit's later incarnations. The purpose of these standards was to set
> arange of line voltages for equipment manufacturers that would beavailable
> across the country.
> The"Ratings" page from the first NEMA standard in 1927 isenclosed. As you
> can see, themaximum line voltage was around 126vac from the very beginning
> of "ACSocket Power." Thelower line voltage limit and the resulting average
> voltage were theonly voltages that changed in all of the subsequent
> standards as this specification was tightened.
>
> Asfor adding a resistance to a silicon diode to better mimic thevoltage
> drop of a Selenium rectifier, it is neither needed nordesired. Simply
> stated, the Selenium rectifier is a crappyrectifier. In addition to taking
> up so much more real estate it isgreatly affected by ambient and operating
> temperature.
> Theaverage voltage drop of a silicon diode is one volt. The averagevoltage
> drop of a Selenium rectifier cell is also one volt. Becausemost Selenium
> rectifiers have a relatively poor reverse voltagerating, most Selenium
> rectifiers are a stack of four or more cells.
> Thisthree volt increase in B+ by changing from Selenium to silicon is
> swamped by the normal line voltagevariation of the AC distribution system.
> If the goal in power supplydesign is to have decent voltage regulation then
> eliminating anyseries resistance will also reduce IR loss which is
> currentdependent, by definition.
> Regards,Jim
> Logic: Method used to arrive at the wrong conclusion, with confidence.?
> Murphy
>
> -----Original Message-----
> From: Les Locklear <leslocklear at hotmail.com>
> To: David Wise <d44617665 at hotmail.com>; Barry <n4buq at knology.net>; R-390
> Mailing List <r-390 at mailman.qth.net>
> Sent: Fri, Oct 7, 2022 12:33 pm
> Subject: Re: [R-390] R-390 Antenna Relay Chatter
>
> >From the "Archives"
>
> DO NOT use the "STANDBY" position on the FUNCTION switch. The now unloaded
> stages will cause the various voltages in the receiver to rise upwards
> perhaps beyond the tolerances of some critical components. This is caused
> by the multiplicity error in our sometimes 120v+ line voltage v/s the 115v
> in use when the 390A was designed and built. Since it is normal for the
> "LOCAL GAIN" control to not completely mute the audio when turned down
> fully, it is natural to consider putting the receiver in "STANDBY."
> Remember, DON'T. Instead, turn the audio down and also back off the RF GAIN
> control to about 11 o'clock and the residual audio will disappear and no
> damage will be done to the receiver.
>
> Les Locklear
> ________________________________
> From: r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net> on
> behalf of David Wise <d44617665 at hotmail.com>
> Sent: Friday, October 7, 2022 12:12 PM
> To: Barry <n4buq at knology.net>; R-390 Mailing List <r-390 at mailman.qth.net>
> Subject: Re: [R-390] R-390 Antenna Relay Chatter
>
> Should not chatter.? #1 suspect is CR801; selenium rectifiers have a
> notorious habit of increasing forward resistance as they age.? Convert to
> silicon plus a resistor in series to mimic the natural forward resistance
> of new selenium.? (I don't know what that value should be.)? This is what
> Tektronix did with their oscilloscopes; for every selenium-powered model,
> they created a silicon retrofit kit.? One of my scopes has one.
>
> Or you can add a reservoir capacitor, starting small and increasing until
> the chatter is reliably gone at low mains voltage.? I am using 100uF.?
> Upside is potentially reduced hum.? Downside is that CR801 will continue to
> deteriorate, so eventually the problem will recur.
>
> HTH,
> Dave Wise
> SWL (inactive)
> ________________________________
> From: r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net> on
> behalf of Barry <n4buq at knology.net>
> Sent: Friday, October 7, 2022 9:59 AM
> To: R-390 Mailing List <r-390 at mailman.qth.net>
> Subject: [R-390] R-390 Antenna Relay Chatter
>
> When in STANDBY, the antenna relay in my R-390 produces a bit of chatter.?
> Is this normal?? I see where that relay is fed, unfiltered, from CR801
> which, from the pictures in the manual, appear to be a stack of selenium
> diodes and I'm wondering if that rectifier stack might be a problem.?
> Anyone know what to expect from that relay in STANDBY and, perhaps, what
> I'm seeing might be normal?
>
> Thanks,
> Barry - N4BUQ
> ______________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:R-390 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> ______________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:R-390 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> ______________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:R-390 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> -------------- next part --------------
> A non-text attachment was scrubbed...
> Name: NEMA 4 Socket Power1927.pdf
> Type: application/pdf
> Size: 211272 bytes
> Desc: not available
> URL: <
> http://mailman.qth.net/pipermail/r-390/attachments/20221007/62a36834/attachment.pdf
> >
>
> ------------------------------
>
> _______________________________________________
> R-390 mailing list
> R-390 at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/r-390
>
>
> End of R-390 Digest, Vol 220, Issue 6
> *************************************
>