[R-390] Tube removal

[wc4g@knology.net]

Barry and all, here are the tube pullers we all really want.
I am continuing to look for more.
Regards,
Don WC4G


On Thu, Jan 6, 2022 at 11:13 AM Barry <n4buq at knology.net> wrote:

> In a pinch (no pun intended), I would think that a pair of common kitchen
> scissor-style tongs with some shrink wrap or thin rubber tubing wrapped
> around the ends would work as well.
>
> I have some of the older Tektronix items (Type 106, Type 191 as well as a
> Type 184 which uses nuvistors).  The 106 and 191 have tubes with IERC
> shields.  I tried to remove one of those shields in the 106 and I simply
> could not pull it loose.  I've used IERC shields before and they can be
> tough to pull when they're locked to the tube base (which they should be to
> work properly) but I simply could not pull hard enough to remove them in
> the 106!
>
> Thanks,
> Barry - N4BUQ
>
> ----- Original Message -----
> > From: "Tisha Hayes" <tisha.hayes at gmail.com>
> > To: "R-390 Mailing List" <r-390 at mailman.qth.net>
> > Sent: Thursday, January 6, 2022 9:52:34 AM
> > Subject: [R-390] Tube removal
>
> > Those "Chinese finger-puzzle" type of grips are still used but on cables;
> > You will find them for suspending coax cables inside of cellular towers
> > from the top and along the midspan. They are known as "Kellum grips".
> >
> > Now, a Kellum grip used for cabling might be a bit too "aggressive" but
> > glass is amazingly resilient when forces are applied equally around their
> > radius. You would need to find a light-duty one.
> >
> > The gorilla tape is a great idea; You can always remove the adhesive from
> > Gorilla tape with the universal solvent... WD-40.
> >
> > Another alternative would be to find an "IERC tube shield".  Those are as
> > rare as hen's-teeth and quite valuable in the tube-radio market. They
> are a
> > black metallic shield that slides down over the top of a tube and are
> used
> > for shielding and thermal dissipation. They have beryllium-copper
> > fingerstock inside of the shields that tightly grabs the tube glass and
> > couples the heat to the metal shield. If you could slide an IERC shield
> > down over the tube you could then grab the top lip of the shield with a
> > pair of needle-nose pliers and rock the tube up and out of the socket in
> a
> > confined space.
> >
> > A bunch of years past I did a writeup on the thermal improvements in a
> > Hammarlund SP-600 (posted on a different list) between unshielded tubes,
> > silver-metallic shielded tubes and IERC shielded tubes on an SP-600 that
> > was installed in a closed cabinet. It involved thermocouples attached to
> > the chassis and key components in multiple locations, regulated AC
> > supplies, temperature controlled rooms and a few weeks of data
> collection.
> > The end result was that the IERC shields did knock down the temperature
> of
> > the chassis by an average of 5c to 15c.  The purpose was in how such
> > temperature reduction would have on extending the life of components like
> > electrolytic capacitors and on frequency drift of the receiver. I do not
> > even have the writeup or data any more; it was lost in one of the many
> hard
> > drive failures that we all experience with computers.
> >
> > I did end up buying a significant quantity of IERC shields and they are
> > still installed on my SP-600-JX17, R-390A and the much despised (by me)
> > CV-591 SSB converter.
> >
> > *Ms. Tisha Hayes*
> >
> > *AA4HA*
> > ______________________________________________________________
> > 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: My R390 back.JPG
Type: image/jpeg
Size: 195404 bytes
Desc: not available
URL: <http://mailman.qth.net/pipermail/r-390/attachments/20220106/47215ca6/attachment-0001.jpe>