[Heathkit] HW-8 tuning capacitor

Fri, 4 Apr 2003 20:51:37 -0500

Yep, I sold those caps for years when I ran Radiokit.
OEP is also the same outfit who made the Tune and Load caps for Heath
linears (except for the early 2 section TRW).
Also made or still make the caps for Dentron, Amp Supply, Ameritron, MFJ and
several others. They also make a clone of the famous Jackson Brothers
reduction drive that mounts on many of those products as well as Heath.
For anyone interested I still have about 100 NOS Jackson drives. I was the
US importer before they went belly up. OEP could never duplicate the quality
or feel. $15 ea shipped.

Carl

----- Original Message -----
From: "John P. Cummins, Sr." <[email protected]>
To: "heathkit" <[email protected]>
Sent: Friday, April 04, 2003 1:11 PM
Subject: [Heathkit] HW-8 tuning capacitor

> I got this from QRP-L.  If it has already been posted, I apologize but I
> know that are a lot of folks with HW-8s that would like to replace their
> tuning caps.
>
> Pickett, AD4S
>
> ...........................
>
> I'd long ago given up hope of finding an exact, drop-in replacement for
the
> VFO tuning capacitor in the HW-8. Every now and then someone asks how to
fix
> the plates on theirs, since they sometimes fall off the shaft.  (The
problem
> is caused by the amount of torque that the reduction drive can supply, as
> explained below, and continuing to turn the knob after the capacitor hits
> the end stops.) Although they can be put back in place it can be a pain
and
> may not last forever, and it would be better to have a replacement
> capacitor.
>
> Suddenly, like a bolt out of the blue, I got e-mail yesterday from Larry
> Baker, WB5OFD, telling me that he tracked down the company that made
> them--still in business--and found that they can still supply the
capacitor.
> He said he's looking at a lot of overtime coming up at work so I offered
to
> post the info for him. He really went beyond the call of duty in tracking
> down the company, and HW-8 owners will be grateful for years to come :-)
>
> And you don't have to own an HW-8 to take advantage of this, since the
> capacitor can be used in any VFO that you might want to build.
>
> Here's his info--
>
> HW-8 VFO Tuning Capacitor
>
> For anyone with an HW-8 collecting dust because of a broken VFO tuning
> capacitor you may take heart, an exact replacement is available.
>
> I recently purchased an HW-8 in which the rotor plates had become detached
> from the tuning shaft.  BIG PROBLEM.  Or at least I thought so.  This HW-8
> was destined to become a spare parts donor.  After removing the capacitor
> from the case I noticed the Heathkit part number 26-152 stamped into the
> frame, as well as the letters ASP*7703.
>
> After a few days of attempting to remember (talking with some old timers)
or
> discover (search the web) who or what ASP stood for, I got lucky.
>
> ASP stands for American Steel Packaging or American Star Products
depending
> on what they manufactured and when.  As you can see from above, 26-152
> ASP*7703 is a Heathkit part number and a manufacturer code.
>
> ASP is now known as Oren Elliot Products.  They are located in Edgerton,
> Ohio, and their plant facilities have been producing capacitors since
l925.
> They are the largest domestic manufacturer of air-dielectric variable
> capacitors.  Their web site can be found at www.orenelliottproducts.com.
>
> With thanks to Mr. Steven Elliot I was able to obtain the following
> information:
>
> The VFO tuning capacitor in the HW-8 is a model NS-51, with direct drive,
> and two rotor and two stator blades with a 0.032" air gap.  It has CCW
> rotation, mounting holes tapped for 6-32 threads, with a trimmer and
copper
> stator blades.  This capacitor has a range of 5.2 pF to 15.1 pF.  The
> trimmer can add 2-15 pF to both the minimum and maximum.
>
> This capacitor, as well as others, was manufactured for the Heathkit
Company
> product line over many years.
>
> Mr. Elliot was also able to shed some light on how this capacitor could be
> easily damaged.  The vernier drive on the HW-8 is a reduction drive
> (planetary) with a probable output torque of about 100 inch ounces.  The
> 26-152 can only stand about 20 inch ounces of pressure (at the end of the
> stop) before succumbing to damage. You would only have to exert an input
> torque force of about three inch ounces on the VFO knob, with the
capacitor
> at the end of its rotation, before possible failure.
>
> I purchased the last 26-152 that was still in stock.  However, the good
news
> is that Mr. Elliott can provide a newly manufactured replacement
capacitor,
> identical to the original 26-152.  Contact him at:  Oren Elliott Products,
> telephone (419) 298-2306, fax (419) 298-3545, or e-mail: [email protected].
In
> case this gets passed on to someone without e-mail, their postal address
is
> 128 W. Vine St., PO Box 638, Edgerton, OH 43517 USA.
>
> Current pricing is:
>
> 1 capacitor:  $14.00
> 2 capacitors:  $11.50 ea.
> 5 capacitors:  $9.50 ea.
>
> OEP also has a slightly different capacitor that may be suitable for use
on
> the HW-8.  It has the same capacitance value; however the shaft is 0.25
> inches longer and it has a built-in 8:1 planetary reduction drive unit.
> This acts as sort of a viscous slip clutch, slipping when the capacitor
> reaches its minimum or maximum rotation. Use of this capacitor would help
> prevent damage as described above but will necessitate a number of changes
> to the original Heathkit design. A new mounting bracket would be required
as
> well as ensuring the VFO dial markings track correctly since this shaft
will
> rotate 8 times faster than the rotor.  I will experiment with this very
soon
> and determine if it is feasible.
>
> If anyone needs an HW-8 VFO tuning capacitor, contact Mr. Elliot and
request
> a direct drive, 26-152 replacement.    Please be sure to thank him for
> supporting QRP ARCI and hams in general.
>
> Larry Baker - WB5OFD [email protected]
>
>
>
> _______________________________________________
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: [email protected] **
> $$ See the vintage area on the HCI web site - http://www.w9wze.org $$
> Heathkit mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/heathkit
>