A Cheaper Way to Repair Porcelain Standoffs
Langford is chief engineer and owner of WGTO(AM/FM) in Cassopolis,
Mich. He writes that one of the mysteries of radio is why porcelain
standoff insulators in phasors and ATU units crack and shatter for no
apparent reason. Larry is sure it has to do with thermal shock and a
host of other things; but there’s no question that when they go,
they need to be fixed.
Larry Langford replaced
costly insulators with PVC.
supports are not cheap, and the replacements are just as fragile. So
you ask yourself if there is a better way.
quick run to the hardware store produced an acceptable replacement
for Larry, and perhaps for you, too. Larry selected 3/4-inch PVC with
end caps. You can fabricate a nice replacement for lower-power
operations that way.
cut the PVC a half-inch shorter than the porcelain standoff and drill
the end caps for 1/4-20 inch stainless hardware. Insert a screw
in the cap and then press it on the PVC tube and mount it to the
panel by screwing the tube down.
Then drill the other end cap and mount the hardware and tighten as
required. Once the hardware is installed, slip the end cap over the
open end of the PVC and you now have a great and cheap replacement.
No need to use PVC cement. The caps will hold fine by friction.
can add PVC cement if you desire, but getting the hardware off after
using the cement will be a challenge. Either way, no more shattered
1 shows a J-Plug jack held with the PVC insulators. Fig. 2 shows
Larry doesn’t know the exact “leakage” of PVC, the voltage
rating is the point of concern. The porcelain insulators are selected
to insulate components from ground. The caution is to not use this
kind of standoff at high current or voltage points within the
received several calls from readers who were delighted with Buc
Fitch’s dummy load project.
RW reader James Walker wasn’t as impressed. He writes: “I
like to build things, too, but how much is your time worth? Even
if the parts were only 20 bucks, the couple of hours spent cobbling
it together had to raise the price well above a hundred.
the Dayton Hamvention a couple of years back, a two-way outfit was
selling 50-watt cell wave reject loads with Type N connectors for 10
bucks each. I bought several. They’re good to well beyond a
gigahertz — 1.1 to 1,” he continued.
I’m on a client’s dime, I’m more than a bit leery of spending
time this way. If it’s my time, I can build another throttle
for my trains in about the same time (and about the same parts cost).
My 2,500-watt Bird oil load was less than a hundred at the
The end caps permit
mounting in low-voltage applications.
is fun, and I’ve ‘imagineered’ all sorts of little gizmos.
But I’ve found that I can buy used and leverage my budgets (both
time and money). Just a thought.”
Fitch thanked Walker for the honest comments. Buc replies further:
know, it’s funny that you should bring forward this thought of time
vs. worth today.I spent the
morning at a hamfest and most of what I saw was, sadly, appliances
operators. People bragging about how well the gear bought from a
catalog from someone else’s recommendation made them unique.
did they bring of themselves? What did they learn? What skills did
they acquire and polish? If you discount snapping cables together or
loading someone else’s software ... they really did not furnish any
personal input,” Buc muses.
radio is just a business or being a ham is just a virtual experience
to you, then more power to you, as you are getting what you want —
which is not much.
dummy load project is not so much about saving money but mainly a
vanity, sanity sort of thing. All the little projects and ideas that
I’ve been writing about over the last 20 years are just departure
points to put your own uniqueness on a final design and assembly. To
wit, our little project to interface computer headsets to balanced
150-ohm inputs has precipitated about 10 permutations from readers.
paraphrase one of my most astute mentors, you learn by doing. You
learn most from your mistakes, which you cannot make unless you do
something ... and what is real thinking but coupling ideas together?
Even a little project like this can yield incredible benefits,
especially for neophytes.”
* * *
manager and engineer Alan Jurison ran across a recall for APC surge
suppressors manufactured before 2003. The affected models are pretty
common; Al has seen them at broadcast stations as well as in his
office! Affected products should be taken out of service immediately
due to the risk of fire, and the owner should be advised to follow
the instructions found on the APC Recall Site: recall.apc.com.
if you did not personally purchase these products, do a thorough
inspection: under desks, inside racks and under consoles. Following a
claims information and validation process, APC is offering customers
a replacement product that is the same model/type, or a functionally
equivalent model, at no charge.
to Workbench. You’ll help your fellow engineers, and qualify for
SBE recertification credit. Send Workbench tips to firstname.lastname@example.org.
Fax to (603) 472-4944.
Author John Bisset
has spent 44 years in the broadcasting industry and is still
learning. He handles West Coast sales for the Telos Alliance. He is
SBE certified and is a past recipient of the SBE’s Educator of the