[R-390] Audio Chassis Mysteries and some power supply stuff

Sun May 13 12:31:28 EDT 2012

Thanks to the group for both on-air and off air comments!

Nice one with the Kielbasa!  I'm going to have to take a closer look at the
tube specs to see some of the details.  It could be an item ripe for
solid-state replacement if they burn out easily and are hard to get.

I will plead guilty to reading stuff waaaay too closely - occupational
hazard in my case.

Speaking of which - I did a curve fit on the rectifier I-V curves and came
up with an equivalent solid-state circuit that matches the straight-line
part of the circuit very well over a good temperature range, if I believe
the Spice models.  I am still thinking about the way to get a gradual turn
on - that might be a fet with a gate that turns on over a specified time
period.  I'll post more separately.  This is not yet built - will probably
order the parts at the same time as audio parts.

I just checked the Pearls - there is more there for me to read than the
Rippel mellow cap mods.  There is a question here over how much to alter a
deck - anything from "unchanged" to Kleronomos to the heck with it, I'm
using an external amp off the detector.  I will probably start with Rippel
mods and work my way up from there.

JPW

On Sat, May 12, 2012 at 12:02 PM, <r-390-request at mailman.qth.net> wrote:

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> Today's Topics:
>
>   1. 4KC Filter (Jim)
>   2. Re: 4KC Filter (chacuff)
>   3.  4KC Filter (Roger Ruszkowski)
>   4. Re: 4KC Filter (Anthony Casorso)
>   5. Re: 4KC Filter (nryan at mchsi.com)
>   6. Audio Chassis mysteries (John Wendler)
>   7. Re: 4KC Filter (Jim)
>   8. Re: Audio Chassis mysteries (Barry)
>   9. Re: Audio Chassis mysteries (chacuff)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 11 May 2012 12:42:23 -0400
> From: "Jim" <jbrannig at verizon.net>
> Subject: [R-390] 4KC Filter
> To: <r-390 at mailman.qth.net>
> Message-ID: <8EFBE3A099C34111BEBD57F0FA3ED36C at DJCK4V71>
> Content-Type: text/plain; format=flowed; charset=iso-8859-1;
>        reply-type=original
>
> I'm in the process of aligning my 67 EAC R-390A.
>
> All is working well except for the 4KC filter, the signal level is about
> half (3db.)  the level of all the other filters.
>
> The trimmers peak normally.
>
> Bad Filter?  I hope not, any other ideas?
>
> Thanks
>
> Jim
>
>
>
> ------------------------------
>
> Message: 2
> Date: Fri, 11 May 2012 13:00:29 -0500
> From: "chacuff" <chacuff at cableone.net>
> Subject: Re: [R-390] 4KC Filter
> To: "Jim" <jbrannig at verizon.net>,       <r-390 at mailman.qth.net>
> Message-ID: <096E420BD9F0425B922A6F2C97C2D592 at acuffmain>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>        reply-type=original
>
> You should note two distinct peaks on each trimmer.  If not then you may
> have to change the padder cap value to get back in resonance.  I've had to
> do that on several occasions where the trimmer only had one peak in 360
> degrees.  Should peak twice 180 degrees out.
>
> If they all do...then you probably have a bad filter.
>
> Cecil
> K5DL
> ----- Original Message -----
> From: "Jim" <jbrannig at verizon.net>
> To: <r-390 at mailman.qth.net>
> Sent: Friday, May 11, 2012 11:42 AM
> Subject: [R-390] 4KC Filter
>
>
> > I'm in the process of aligning my 67 EAC R-390A.
> >
> > All is working well except for the 4KC filter, the signal level is about
> > half (3db.)  the level of all the other filters.
> >
> > The trimmers peak normally.
> >
> > Bad Filter?  I hope not, any other ideas?
> >
> > Thanks
> >
> > Jim
> >
> > ______________________________________________________________
> > 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
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>
>
> ------------------------------
>
> Message: 3
> Date: Fri, 11 May 2012 18:52:04 -0400 (EDT)
> From: Roger Ruszkowski <flowertime01 at wmconnect.com>
> Subject: [R-390]  4KC Filter
> To: R-390 at mailman.qth.net
> Message-ID: <8CEFDDFD1CF4E07-203C-20C50 at webmail-m054.sysops.aol.com>
> Content-Type: text/plain; charset="us-ascii"
>
>
> Jim,
>
> If you need a replacement filter, Fair Radio in Ohio had a bunch of 4KC
> pulls. 2KC are plum gone.
>
> We fellows discovered some time back that the foam padding inside turns to
> a black tar like gunk.
>
> A bit of ugly stuff will drift around and glum onto the wafer core stack
> that makes up the filter.
> It is literally a mechanical device inside the can. this will pad the
> filter stack and cause a loss.
> Half power is about expected. The filter band width is also not likely 4KC
> any more.
>
> The filter can, can be de soldered, opened, cleaned, repaired, coils
> rewound if needed, new foam instaled and then the can re soldered.
>
> Another used item is not likely to look any better inside.
>
> Also consider a cold solder joint in the circuit before you just pull the
> filter.
>
> Roger AI4NI
>
>
>
>
> I'm in the process of aligning my 67 EAC R-390A.
> All is working well except for the 4KC filter, the signal level is about
> alf (3db.)  the level of all the other filters.
> The trimmers peak normally.
> Bad Filter?  I hope not, any other ideas?
> Thanks
> Jim
>
>
>
> ------------------------------
>
> Message: 4
> Date: Fri, 11 May 2012 19:37:31 -0600
> From: Anthony Casorso <canthony15 at msn.com>
> Subject: Re: [R-390] 4KC Filter
> To: <jbrannig at verizon.net>, <r-390 at mailman.qth.net>
> Message-ID: <SNT132-W37AD311F9D8959583DBB9AC9140 at phx.gbl>
> Content-Type: text/plain; charset="iso-8859-1"
>
>
> My 67 EAC is the same way. Down about half on 4KHz. I have measured the
> bandwidth and it is still fairly close to 4KHz. I just let the AGC make it
> up but I have been considering a new filter.
> Tony
>
> > From: jbrannig at verizon.net
> > To: r-390 at mailman.qth.net
> > Date: Fri, 11 May 2012 12:42:23 -0400
> > Subject: [R-390] 4KC Filter
> >
> > I'm in the process of aligning my 67 EAC R-390A.
> >
> > All is working well except for the 4KC filter, the signal level is about
> > half (3db.)  the level of all the other filters.
> >
> > The trimmers peak normally.
> >
> > Bad Filter?  I hope not, any other ideas?
> >
> > Thanks
> >
> > Jim
> >
>
>
>
> ------------------------------
>
> Message: 5
> Date: Fri, 11 May 2012 21:37:48 -0500 (CDT)
> From: nryan at mchsi.com
> Subject: Re: [R-390] 4KC Filter
> To: r-390 at mailman.qth.net
> Message-ID:
>        <1796357101.13710131336790268320.JavaMail.root at dsmdc-mail-mbs11>
> Content-Type: text/plain; charset=utf-8
>
> I would first ask myself if the receiver is seriously impaired with an
> under-performing 4 KC filter.  I have one such and compensate for it by
> turning up the volume a bit.
>
> These filters are increasingly hard to come by and best reserved for
> instances of open or shorted filters.
>
> Just my .02.
>
> Norman, KG4SWM
>
> Any activity becomes creative when the doer cares about doing it right, or
> doing it better. -- John Updike
>
>
> ----- Original Message -----
> From: Anthony Casorso <canthony15 at msn.com>
> To: jbrannig at verizon.net, r-390 at mailman.qth.net
> Sent: Fri, 11 May 2012 20:37:31 -0500 (CDT)
> Subject: Re: [R-390] 4KC Filter
>
>
> My 67 EAC is the same way. Down about half on 4KHz. I have measured the
> bandwidth and it is still fairly close to 4KHz. I just let the AGC make it
> up but I have been considering a new filter.
> Tony
>
> > From: jbrannig at verizon.net
> > To: r-390 at mailman.qth.net
> > Date: Fri, 11 May 2012 12:42:23 -0400
> > Subject: [R-390] 4KC Filter
> >
> > I'm in the process of aligning my 67 EAC R-390A.
> >
> > All is working well except for the 4KC filter, the signal level is about
> > half (3db.)  the level of all the other filters.
> >
> > The trimmers peak normally.
> >
> > Bad Filter?  I hope not, any other ideas?
> >
> > Thanks
> >
> > Jim
> >
>
>
> ______________________________________________________________
> R-390 mailing list
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>
>
> ------------------------------
>
> Message: 6
> Date: Sat, 12 May 2012 00:33:53 -0400
> From: John Wendler <wendlerjrv at gmail.com>
> Subject: [R-390] Audio Chassis mysteries
> To: r-390 at mailman.qth.net
> Message-ID:
>        <CAJBkcK7=koT4sFzT2+_-XAPF65TK=47do5ffPigb1vUwR_EFvQ at mail.gmail.com
> >
> Content-Type: text/plain; charset=ISO-8859-1
>
> I'm doing some resistance probing on the dismounted audio chassis.  Setting
> aside the out of spec carbon comp resistors that should really be replaced
> with higher power metal film units.... oh, that would only be all of
> them....
>
> I measure the following:
>
> FL601
> Wh/Blk wire terminal to center: open (instead of 230 or 250)
> Wh/Red wire terminal to center: 958 Ohms (instead of 230 or 250)
> Wh/Red wire terminal to White/Black wire terminal: open (instead of 480)
>
> In Fig 52 of the tech manual, which shows a bottom view photo of the
> chassis, I note an R-628 that is missing from my Moto audio module.  Does
> anyone know what is up with that?
>
> My FL-601 would appear to be broken; I'm not sure how that can occur...  It
> is a low power filter for such a big can - rated at 5 mW but with very
> stiff I/O impedances.  I would guess miles of very fine wire.  I may take
> this apart, yet.
>
> In other measurements:
>
> K601: spot on at 2.8 ohms
> L601: somewhat low at 104.5 vs. 137 ohms in the manual; the can says less
> than 137 ohms, and it is, but is it enough low to indicate shorted turns?
> L602: slightly low at 117.7 vs. 125
> L603: slightly low at 92.3 vs. 110
>
> T601
> 1-2: 597 vs. 580
> 3-4: 27.3 vs. 28
> 5-6: 28.5 vs. 30
>
> T602
> 1-2: 577 vs. 588
> 3-4: 27.4 vs. 28
> 5-6: 29.9 vs. 30
>
> I do not know yet whether the difference in the measured transformer
> primary resistances is caused by leakage elsewhere in the circuit - I would
> otherwise expect them to be closer to equal.
>
> Does anyone know what RT510 is?  the 5 in the number would appear to
> indicate IF chassis, but it appears in audio chassis on pg 93 of the manual
> in the resistance measurements.
>
> The caps are going to get replaced; I will be doing the "Mellow Cap"
> improvement.
>
> 73 de John N5CQU
>
>
> ------------------------------
>
> Message: 7
> Date: Sat, 12 May 2012 08:12:04 -0400
> From: "Jim" <jbrannig at verizon.net>
> Subject: Re: [R-390] 4KC Filter
> To: <R-390 at mailman.qth.net>
> Message-ID: <B853546B98584CC0BDA9D6ADD04DBA76 at DJCK4V71>
> Content-Type: text/plain; format=flowed; charset=iso-8859-1;
>        reply-type=original
>
>
> Thank you all for the responses.
> I've had a lot of Collins gear and this is my first Filter failure.
>
> The receiver still performs at 4kc. and I will leave it alone.
>
> Rebuilding the filter per the Y2K manual is an option I will leave for
> another day.
>
> Well, one more tweak on the alignment and I'll fire up the forklift and put
> the radio back in the rack.
>
>
>
> 73,
>  Jim
>
>
>
> ------------------------------
>
> Message: 8
> Date: Sat, 12 May 2012 09:19:26 -0400
> From: Barry <n4buq at knology.net>
> Subject: Re: [R-390] Audio Chassis mysteries
> To: <r-390 at mailman.qth.net>, "John Wendler" <wendlerjrv at gmail.com>
> Message-ID: <63354.1336828766 at knology.net>
> Content-Type: text/plain; charset="utf-8"
>
>
> > Does anyone know what RT510 is?  the 5 in the number would appear to
> > indicate IF chassis, but it appears in audio chassis on pg 93 of the
> > manualin the resistance measurements.
> >
> > The caps are going to get replaced; I will be doing the "Mellow Cap"
> > improvement.
> >
> > 73 de John N5CQU
>
> RT510 is the 3TF7 ballast tube.  It is on the IF chassis.
>
> 73,
> Barry - N4BUQ
>
>
>
> ------------------------------
>
> Message: 9
> Date: Sat, 12 May 2012 10:49:05 -0500
> From: "chacuff" <chacuff at cableone.net>
> Subject: Re: [R-390] Audio Chassis mysteries
> To: <n4buq at knology.net>, <r-390 at mailman.qth.net>,       "John Wendler"
>        <wendlerjrv at gmail.com>
> Message-ID: <28F6C04EA9474965A43C83CBEF52239F at acuffmain>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>        reply-type=original
>
> That's Rear Tied 5" Kielbasa in a #10 casing.  (RT-510)  Sometimes referred
> to as a 3TF7. (a common sub that's Kosher) Keeps everything working within
> spec as the voltage varies...  Generates a nice odor in a boatanchor.  Any
> oil it generates works good to lubricate the gear train as well....
>
> Back in hiding now...
>
> Cecil
> K5DL
> ----- Original Message -----
> From: "Barry" <n4buq at knology.net>
> To: <r-390 at mailman.qth.net>; "John Wendler" <wendlerjrv at gmail.com>
> Sent: Saturday, May 12, 2012 8:19 AM
> Subject: Re: [R-390] Audio Chassis mysteries
>
>
> >
> >> Does anyone know what RT510 is?  the 5 in the number would appear to
> >> indicate IF chassis, but it appears in audio chassis on pg 93 of the
> >> manualin the resistance measurements.
> >>
> >> The caps are going to get replaced; I will be doing the "Mellow Cap"
> >> improvement.
> >>
> >> 73 de John N5CQU
> >
> > RT510 is the 3TF7 ballast tube.  It is on the IF chassis.
> >
> > 73,
> > Barry - N4BUQ
> >
> > ______________________________________________________________
> > R-390 mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/r-390
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> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
>
>
>
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>
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> End of R-390 Digest, Vol 97, Issue 9
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>