[R-390] R-390 Digest, Vol 224, Issue 4

Sun Feb 26 22:50:31 EST 2023

Thank you!  Nice trick with the current limiter!

On Sun, Feb 26, 2023 at 9:33 PM <r-390-request at mailman.qth.net> wrote:

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> Today's Topics:
>
>    1. Re: C553 replacement? (Jim Whartenby)
>    2. Re: C553 replacement? (David Wise)
>    3. Re: C553 replacement? (Dan Martin)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sun, 26 Feb 2023 21:32:20 +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] C553 replacement?
> Message-ID: <1125916661.1205650.1677447140594 at mail.yahoo.com>
> Content-Type: text/plain; charset=UTF-8
>
> Dave
> I can verify that C606 in TM 11-5820-357-35P is listed as type
> CP10A1EE224M as stated?but the Collins Preliminary R-390 Manual on page 186
> does list C608 as 0.22uF, +/- 20% at 100vdcw and gives a Sprague P/N,
> 96P22403S13.? Perhaps a misprint by Collins that was caught when the
> official military manuals were issued?
>
> Regards,
> Jim
>
> Logic: Method used to arrive at the wrong conclusion, with confidence.?
> Murphy
>
> -----Original Message-----
> From: David Wise <d44617665 at hotmail.com>
> To: Barry <n4buq at knology.net>; Jim Whartenby <old_radio at aol.com>
> Cc: R-390 Mailing List <r-390 at mailman.qth.net>
> Sent: Sun, Feb 26, 2023 2:15 pm
> Subject: RE: C553 replacement?
>
> #yiv7570053998 filtered {}#yiv7570053998 filtered {}#yiv7570053998
> p.yiv7570053998MsoNormal, #yiv7570053998 li.yiv7570053998MsoNormal,
> #yiv7570053998 div.yiv7570053998MsoNormal
> {margin:0in;font-size:11.0pt;font-family:sans-serif;}#yiv7570053998 a:link,
> #yiv7570053998 span.yiv7570053998MsoHyperlink
> {color:blue;text-decoration:underline;}#yiv7570053998
> .yiv7570053998MsoChpDefault {}#yiv7570053998 filtered {}#yiv7570053998
> div.yiv7570053998WordSection1 {}That?s correct, C553 is a coupling cap into
> the R-390A mechanical filter.? It?s a catastrophe if it shorts.? Many
> people replace it even though it?s a Vitamin Q which should still be good.?
> I kept the old cap and inserted a current limiter, using a Supertex (now
> Microchip) LND-150 depletion-mode MOSFET.? Just connect drain upstream, and
> source & gate downstream, and voila, 1mA limit. ? In the R-390, C606 sees
> 1/19th of 180V so it will last forever.? C608 sees about 180-10+5 or 175V.?
> If it leaks, the regulator will throttle down
>  .? If you suspect this, measure voltage across 6BH6 grid resistor R624;
> it should be zero.? Slight leakage is worse than severe leakage, because
> the 6080?s will overheat. ? On pdf page 10 of 34 of TM 11-5820-357-35P,
> C608 is listed as type CP10A1EE224M.? CP is hermetically-sealed paper.? In
> specification MIL-C-25D, the second E indicates 400 volts. ? Dave WiseSWL
> (Inactive) ? Sent from Mail for Windows ? From: Barry
> Sent: Saturday, February 25, 2023 8:08 PM
> To: Jim Whartenby
> Cc: R-390 Mailing List
> Subject: Re: [R-390] C553 replacement? ? I think C553 is only in the R390A.
>
> Thanks,
> Barry - N4BUQ
>
> ----- Original Message -----
> > From: "R-390 Mailing List" <r-390 at mailman.qth.net>
> > To: "R-390 Mailing List" <r-390 at mailman.qth.net>
> > Sent: Saturday, February 25, 2023 10:03:27 PM
> > Subject: Re: [R-390] C553 replacement?
>
> > A quick look at the R-390 Collins preliminary manual indicates that
> C-606 and
> > C-608 are both rated at 100 vdcw.? Curious that C-608 has 174 volts
> across it
> > according to the voltage table for V-607.
> >
> > I did not find C553, which tube is associated with it?
> >
> > Regards,
> > Jim
> >
> > Logic: Method used to arrive at the wrong conclusion, with confidence.?
> Murphy
> >
> > -----Original Message-----
> > From: Barry <n4buq at knology.net>
> > To: John Wendler <wendlerjrv at gmail.com>
> > Cc: R-390 Mailing List <r-390 at mailman.qth.net>
> > Sent: Sat, Feb 25, 2023 8:52 pm
> > Subject: Re: [R-390] C553 replacement?
> >
> > If I'm not mistaken, Dave Medley (and others) suggest that 180v
> regulator issues
> > in the R390 might be due to leakage in C606 and/or C608 and I think
> those are
> > typically Vitamin Q capacitors.
> >
> > Thanks,
> > Barry - N4BUQ
> >
> > ----- Original Message -----
> >> From: "John Wendler" <wendlerjrv at gmail.com>
> >> To: "R-390 Mailing List" <r-390 at mailman.qth.net>
> >> Sent: Saturday, February 25, 2023 6:01:07 PM
> >> Subject: [R-390] C553 replacement?
> >
> >> The C553 in one of my IF modules is a Sangamo Vitamin Q capacitor, 0.01
> uF,
> >> 300 V.? It looks good visually and is not a Brown or Black Beauty of
> >> Death.
> >>
> >> What's the group experience with the reliability of the Vitamin Q caps?
> >>
> >> V/r,
> >>
> >> JP N5CQU
> >> ______________________________________________________________
> >> R-390 mailing list
> >> Home: http://mailman.qth.net/mailman/listinfo/r-390
> >> Help: http://mailman.qth.net/mmfaq.htm
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> >> This list hosted by: http://www.qsl.net
> >> Please help support this email list: http://www.qsl.net/donate.html
> > ______________________________________________________________
> > R-390 mailing list
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> ------------------------------
>
> Message: 2
> Date: Sun, 26 Feb 2023 23:04:18 +0000
> From: David Wise <d44617665 at hotmail.com>
> To: Jim Whartenby <old_radio at aol.com>, "r-390 at mailman.qth.net"
>         <r-390 at mailman.qth.net>
> Subject: Re: [R-390] C553 replacement?
> Message-ID:
>         <
> BY5PR04MB68202A6E6EF2A7D008834C62AEAE9 at BY5PR04MB6820.namprd04.prod.outlook.com
> >
>
> Content-Type: text/plain; charset="Windows-1252"
>
> Sprague type 96P is a Vitamin Q impregnated hermetic paper cap rated for
> 125C operation.  In the 1972 United Technical Publications ?Master? 37th
> edition, Section 1500, source page 212, Sprague advertises that they exceed
> MIL-C-25A, the military specification for style CPxx.
>
> Dave
>
> Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows
>
> From: Jim Whartenby via R-390<mailto:r-390 at mailman.qth.net>
> Sent: Sunday, February 26, 2023 1:32 PM
> To: r-390 at mailman.qth.net<mailto:r-390 at mailman.qth.net>
> Subject: Re: [R-390] C553 replacement?
>
> Dave
> I can verify that C606 in TM 11-5820-357-35P is listed as type
> CP10A1EE224M as stated but the Collins Preliminary R-390 Manual on page 186
> does list C608 as 0.22uF, +/- 20% at 100vdcw and gives a Sprague P/N,
> 96P22403S13.  Perhaps a misprint by Collins that was caught when the
> official military manuals were issued?
>
> Regards,
> Jim
>
> Logic: Method used to arrive at the wrong conclusion, with confidence.
> Murphy
>
> -----Original Message-----
> From: David Wise <d44617665 at hotmail.com>
> To: Barry <n4buq at knology.net>; Jim Whartenby <old_radio at aol.com>
> Cc: R-390 Mailing List <r-390 at mailman.qth.net>
> Sent: Sun, Feb 26, 2023 2:15 pm
> Subject: RE: C553 replacement?
>
> #yiv7570053998 filtered {}#yiv7570053998 filtered {}#yiv7570053998
> p.yiv7570053998MsoNormal, #yiv7570053998 li.yiv7570053998MsoNormal,
> #yiv7570053998 div.yiv7570053998MsoNormal
> {margin:0in;font-size:11.0pt;font-family:sans-serif;}#yiv7570053998 a:link,
> #yiv7570053998 span.yiv7570053998MsoHyperlink
> {color:blue;text-decoration:underline;}#yiv7570053998
> .yiv7570053998MsoChpDefault {}#yiv7570053998 filtered {}#yiv7570053998
> div.yiv7570053998WordSection1 {}That?s correct, C553 is a coupling cap into
> the R-390A mechanical filter.  It?s a catastrophe if it shorts.  Many
> people replace it even though it?s a Vitamin Q which should still be good.
> I kept the old cap and inserted a current limiter, using a Supertex (now
> Microchip) LND-150 depletion-mode MOSFET.  Just connect drain upstream, and
> source & gate downstream, and voila, 1mA limit.   In the R-390, C606 sees
> 1/19th of 180V so it will last forever.  C608 sees about 180-10+5 or 175V.
> If it leaks, the regulator will throttle down
>  .  If you suspect this, measure voltage across 6BH6 grid resistor R624;
> it should be zero.  Slight leakage is worse than severe leakage, because
> the 6080?s will overheat.   On pdf page 10 of 34 of TM 11-5820-357-35P,
> C608 is listed as type CP10A1EE224M.  CP is hermetically-sealed paper.  In
> specification MIL-C-25D, the second E indicates 400 volts.   Dave WiseSWL
> (Inactive)   Sent from Mail for Windows   From: Barry
> Sent: Saturday, February 25, 2023 8:08 PM
> To: Jim Whartenby
> Cc: R-390 Mailing List
> Subject: Re: [R-390] C553 replacement?   I think C553 is only in the R390A.
>
> Thanks,
> Barry - N4BUQ
>
> ----- Original Message -----
> > From: "R-390 Mailing List" <r-390 at mailman.qth.net>
> > To: "R-390 Mailing List" <r-390 at mailman.qth.net>
> > Sent: Saturday, February 25, 2023 10:03:27 PM
> > Subject: Re: [R-390] C553 replacement?
>
> > A quick look at the R-390 Collins preliminary manual indicates that
> C-606 and
> > C-608 are both rated at 100 vdcw.  Curious that C-608 has 174 volts
> across it
> > according to the voltage table for V-607.
> >
> > I did not find C553, which tube is associated with it?
> >
> > Regards,
> > Jim
> >
> > Logic: Method used to arrive at the wrong conclusion, with confidence.
> Murphy
> >
> > -----Original Message-----
> > From: Barry <n4buq at knology.net>
> > To: John Wendler <wendlerjrv at gmail.com>
> > Cc: R-390 Mailing List <r-390 at mailman.qth.net>
> > Sent: Sat, Feb 25, 2023 8:52 pm
> > Subject: Re: [R-390] C553 replacement?
> >
> > If I'm not mistaken, Dave Medley (and others) suggest that 180v
> regulator issues
> > in the R390 might be due to leakage in C606 and/or C608 and I think
> those are
> > typically Vitamin Q capacitors.
> >
> > Thanks,
> > Barry - N4BUQ
> >
> > ----- Original Message -----
> >> From: "John Wendler" <wendlerjrv at gmail.com>
> >> To: "R-390 Mailing List" <r-390 at mailman.qth.net>
> >> Sent: Saturday, February 25, 2023 6:01:07 PM
> >> Subject: [R-390] C553 replacement?
> >
> >> The C553 in one of my IF modules is a Sangamo Vitamin Q capacitor, 0.01
> uF,
> >> 300 V.  It looks good visually and is not a Brown or Black Beauty of
> >> Death.
> >>
> >> What's the group experience with the reliability of the Vitamin Q caps?
> >>
> >> V/r,
> >>
> >> JP N5CQU
> >> ______________________________________________________________
> >> 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
> ______________________________________________________________
> 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: Sun, 26 Feb 2023 21:32:48 -0500
> From: Dan Martin <pitfit at comcast.net>
> To: David Wise <d44617665 at hotmail.com>
> Cc: R-390 Mailing List <r-390 at mailman.qth.net>
> Subject: Re: [R-390] C553 replacement?
> Message-ID: <2E5DA7BC-DD72-47B5-979B-B76E422A1895 at comcast.net>
> Content-Type: text/plain; charset=utf-8
>
> ??I've read these recent C553 posts with interest and a grin.
>
> 10-20 years ago there were stories alleged of hundreds of destroyed
> mechanical filters due to stock C553 failures. Puzzled operators, concerned
> about the mysterious loss of a filter, would quickly switch to each of the
> alternate filters to confirm their function and would thereby sequentially
> destroy the entire filter bank. Who hasn't heard those stories around a
> campfire?
>
> Replacing C553 with a Sprague (now CDE) Orange Drop used to be the
> unquestioned first thing in any refurbishment. Chuck Rippel wouldn't let a
> 390A leave his shop without an Orange Drop in place for C553.
>
> Now it seems Vitamin Q's, like Golden Retrievers, are our best friends and
> never turn on us and go bad.
>
> Really, not picking a fight, my friends. Just appreciating the comments
> re: what had been unquestioned convention "back in the day."
>
> And yes, my '67 EAC has a 20 year old by-gawd Sprague Orange Drop in place
> for C553, not some  upstart CDE branded version. ?
>
> Dan
> WB4GRA
>
> Sent from my iPhone
>
> > On Feb 26, 2023, at 3:16 PM, David Wise <d44617665 at hotmail.com> wrote:
> > ?That?s correct, C553 is a coupling cap into the R-390A mechanical
> filter.  It?s a catastrophe if it shorts.  Many people replace it even
> though it?s a Vitamin Q which should still be good.  I kept the old cap and
> inserted a current limiter, using a Supertex (now Microchip) LND-150
> depletion-mode MOSFET.  Just connect drain upstream, and source & gate
> downstream, and voila, 1mA limit.
> >
> > In the R-390, C606 sees 1/19th of 180V so it will last forever.  C608
> sees about 180-10+5 or 175V.  If it leaks, the regulator will throttle
> down.  If you suspect this, measure voltage across 6BH6 grid resistor R624;
> it should be zero.  Slight leakage is worse than severe leakage, because
> the 6080?s will overheat.
> >
> > On pdf page 10 of 34 of TM 11-5820-357-35P, C608 is listed as type
> CP10A1EE224M.  CP is hermetically-sealed paper.  In specification
> MIL-C-25D, the second E indicates 400 volts.
> >
> > Dave Wise
> > SWL (Inactive)
> >
> > Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for
> Windows
> >
> > From: Barry<mailto:n4buq at knology.net>
> > Sent: Saturday, February 25, 2023 8:08 PM
> > To: Jim Whartenby<mailto:old_radio at aol.com>
> > Cc: R-390 Mailing List<mailto:r-390 at mailman.qth.net>
> > Subject: Re: [R-390] C553 replacement?
> >
> > I think C553 is only in the R390A.
> >
> > Thanks,
> > Barry - N4BUQ
> >
> > ----- Original Message -----
> >> From: "R-390 Mailing List" <r-390 at mailman.qth.net>
> >> To: "R-390 Mailing List" <r-390 at mailman.qth.net>
> >> Sent: Saturday, February 25, 2023 10:03:27 PM
> >> Subject: Re: [R-390] C553 replacement?
> >
> >> A quick look at the R-390 Collins preliminary manual indicates that
> C-606
>
>
>
> ------------------------------
>
> _______________________________________________
> R-390 mailing list
> R-390 at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/r-390
>
>
> End of R-390 Digest, Vol 224, Issue 4
> *************************************
>