[NJARC] 3RP1 CR tube/Heathkit HO-10 Monitor Scope

Fri Aug 14 11:49:42 EDT 2009

Hi John-
The power transformer seeks ok: I have not tested outputs yet, but the windings are all in good shape: Continuity through each, and none to other windings or to the frame. Should be ok, but I know where I can get it fixed if necessary.

I took the tube out first, in prep to tear it down... Should have it done over the weekend... I got the unit cheap(for e-bay) at around $30. :) I have been doing some upgrades- like the usual cap upgrades, etc. I just hope the scope tube works well! Otherwise I'll have to find one.

Scott

--- On Fri, 8/14/09, John Ruccolo <jr6v6gt at yahoo.com> wrote:

> From: John Ruccolo <jr6v6gt at yahoo.com>
> Subject: Re: [NJARC] 3RP1 CR tube/Heathkit HO-10 Monitor Scope
> To: "NJARC Radio Club" <njarc at mailman.qth.net>, "Scott Roberts" <ng19delta at yahoo.com>
> Date: Friday, August 14, 2009, 11:32 AM
> Scott,
> 
> From your note, it sounded like you were done already, and
> then the "CRT Incident" happened.
> 
> BTW, did you test the power xformer on that HO-10 first?
> They have a reputation for failing.
> 
> 
> JR
> 
> --- On Thu, 8/13/09, Scott Roberts <ng19delta at yahoo.com>
> wrote:
> 
> > From: Scott Roberts <ng19delta at yahoo.com>
> > Subject: Re: [NJARC] 3RP1 CR tube/Heathkit HO-10
> Monitor Scope
> > To: "NJARC Radio Club" <njarc at mailman.qth.net>,
> "John Ruccolo" <jr6v6gt at yahoo.com>
> > Date: Thursday, August 13, 2009, 10:56 PM
> > Thanks John.
> > 
> >  Mention it AFTER I start why dontcha!... LOL...
> However,
> > it has helped expose several defects with the unit: I
> found
> > one resistor which had obviously overheated the wire
> next to
> > it, as I found them welded together... I also found a
> > broken(clean in half!) resistor in one spot, and a
> couple
> > other things. I am just annoyed I forgot to order the
> 3
> > .22/600 caps I needed for it when I placed a large
> > electrolytic order with Just Radios. (I can't use
> > electrolytics in place of paper caps I'm sure...) I am
> also
> > starting to swap in X-Y caps on the 120AC line on most
> of my
> > machines. 
> > 
> > I found one problem with my shop: I have been getting
> bits
> > together for so many different radios, I lost track of
> what
> > goes to whom! So I spent last night after work sorting
> caps
> > (mylar, electrolytics, and those little flat ones John
> likes
> > to supply us with ;)) into little plastic buckets
> labeled
> > for each radio. It is now a very organized little pile
> of
> > caps :) I have about 6 radios/components & power
> > supplies to recap!
> > 
> > Scott
> > 
> > 
> > 
> > --- On Thu, 8/13/09, John Ruccolo <jr6v6gt at yahoo.com>
> > wrote:
> > 
> > > From: John Ruccolo <jr6v6gt at yahoo.com>
> > > Subject: Re: [NJARC] 3RP1 CR tube/Heathkit HO-10
> > Monitor Scope
> > > To: "NJARC Radio Club" <njarc at mailman.qth.net>,
> > "Scott Roberts" <ng19delta at yahoo.com>
> > > Date: Thursday, August 13, 2009, 9:26 PM
> > > Hi Scott,
> > > 
> > > It's NEVER easy with you, is it? ;-)
> > > 
> > > Pardon the pun, but in the future you should
> resist
> > the
> > > temptation to "re-resistor" a piece of gear.
> That
> > HO-10 is
> > > fairly modern, and most if not all of the
> resistors
> > were
> > > probably still good (within tolerance, or at
> least
> > close).
> > > 
> > > Think about it -- you didn't "re-resistor" that
> > 70-plus
> > > year old Hallicrafters SX-16, why do it to a
> piece of
> > gear
> > > only half that age?
> > > 
> > > The more parts you replace, the better your
> chances
> > of
> > > making a silly wiring error that can be
> *extremely*
> > > difficult for you (OR YOUR FREINDS) to catch. By
> all
> > means,
> > > get rid if the paper caps. But resistors are
> usually
> > > presumed innocent until proven guilty.
> > > 
> > > 
> > > Folks, feel free to chime in.
> > > 
> > > 
> > > Regards,
> > > 
> > > John R.
> > > 
> > > 
> > > 
> > > --- On Wed, 8/12/09, Scott Roberts <ng19delta at yahoo.com>
> > > wrote:
> > > 
> > > > From: Scott Roberts <ng19delta at yahoo.com>
> > > > Subject: [NJARC] 3RP1 CR tube/Heathkit
> HO-10
> > Monitor
> > > Scope
> > > > To: "NJARC Radio Club" <njarc at mailman.qth.net>
> > > > Date: Wednesday, August 12, 2009, 1:22 PM
> > > > Just remember 
> > > > Reply = Poster
> > > > Reply All = Everyone
> > > > 
> > > >
> > >
> >
> _________________________________________________________
> > > > Wow... Long Subject line...
> > > > 
> > > > Anyway, Simple question: First(as usual)
> the
> > > backstory:
> > > > 
> > > > I purchased the HO-10 scope with a couple
> known
> > > problems,
> > > > so I decided to follow advice from a guy
> who
> > works on
> > > them
> > > > and not only recap, but re-resistor the
> whole
> > item.
> > > No
> > > > problem, simple stuff. However, in so doing,
> when
> > I
> > > went to
> > > > remove the CRT tube (3RP1) the base cap
> pulled
> > off
> > > the
> > > > wires! It was held very tightly by the
> socket,
> > and
> > > literally
> > > > pulled off the end: the adhesive had given
> up
> > the
> > > ghost, and
> > > > they pulled free of the solder, or the very
> ends
> > of
> > > the
> > > > wires came off.
> > > > 
> > > > So now I have an unkeyed tube with a bunch
> of
> > good
> > > > condition wires, and a cap to refit.
> > > > 
> > > > Looking at the schematic, would it be
> correct to
> > > assume
> > > > that the only two wires I could read
> continuity
> > > between
> > > > would be the heater connections? I looked
> over
> > the
> > > schematic
> > > > and found pins 5 & 11 were not used by
> the
> > tube
> > > itself,
> > > > and I determined where the gaps between
> wires
> > were
> > > spaced to
> > > > go to the pins on either side. I then looked
> at
> > the
> > > line
> > > > burned into the screen, and determined
> > orientation,
> > > and
> > > > checked alignment with the cap. It appeared
> to
> > be
> > > correct,
> > > > and my thought was that I could confirm by
> > checking
> > > > continuity through the heater, as it would
> be the
> > only
> > > place
> > > > I would find it. I assembled the cap to the
> tube
> > > after
> > > > cleaning, fluxing & tinning the leads,
> just
> > have
> > > to find
> > > > my Duco cement to glue the base.
> > > > 
> > > > Simply put, is my above assumption correct?
> > > > 
> > > > 
> > > > Thanks!
> > > > Scott
> > > >
> > >
> >
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> > >       
> > >
> > 
> 
> 
> 
> 