Consider an alternate universe where you and I lived in the same
neighborhood. Ken and Bill were our scoutmasters. The things that
could have been achieved.... but wait, Jaime was there too, we got
distracted... but had a hell of a lot of fun!!!
*From:* Chuck Macenski
*Sent:* Sunday, July 21, 2019 2:50 PM
*To:* AnimalFarm Microwave Users Group
*Subject:* Re: [AFMUG] OT 50 years ago
I still own one of these. It got me started
On Sun, Jul 21, 2019 at 2:22 PM <[email protected]> wrote:
http://www.radioshackcatalogs.com/html/1969/hr124.html
It was still kicking around a few years ago.
That was probably the best xmas gift my folks ever gave me.
*From:* Ken Hohhof
*Sent:* Sunday, July 21, 2019 11:21 AM
*To:* 'AnimalFarm Microwave Users Group'
*Subject:* Re: [AFMUG] OT 50 years ago
I had a Knight 12-in-1 lab kit (page 65 in the catalog).____
https://www.americanradiohistory.com/Archive-Catalogs/Allied-Catalogs/Allied-Catalog-1963.pdf____
____
I also remember taking tubes to the drug store with a tube tester.
Often a TV had several tubes of the same type (6SN7 or 12AX7 or
12AU7) and you could just play musical chairs until the weak one
ended up in a less critical location. That or you called the TV
repairman to come out to your house. Once the transistor sets came
out though, he would always say “the board” needed to be replaced,
and at that point you might as well buy a new set.____
____
____
*From:*AF <[email protected]> *On Behalf Of *Chuck McCown
*Sent:* Sunday, July 21, 2019 11:12 AM
*To:* AnimalFarm Microwave Users Group <[email protected]>
*Subject:* Re: [AFMUG] OT 50 years ago____
____
I spent hours at 2 am trying to improve the convergence on my
parents color set as that is when the test pattern were on. ____
____
I used to feed audio into the vertical deflection coils of old B&W
TVs trying to make a rudimentary oscilloscope. Probably was all of
10 years old at the time. Kids used to have much more fun than they
do now. I also had saltpeter...____
____
*From:*Bill Prince ____
*Sent:*Sunday, July 21, 2019 10:05 AM____
*To:*[email protected] ____
*Subject:*Re: [AFMUG] OT 50 years ago____
____
Black and white TVs just shot one beam; color would shoot 3 beams.
The beams would just go straight out to the center of the screen
without any steering. That's why one of the failure modes was just a
glowing dot in the center of the screen. Steering was done with
electromagnets in the form of a "yoke" wrapped around the neck of
the CRT. One pair for horizontal scan, and one pair for vertical
scan. Black and white was pretty simple, but color had all kinds of
issues because the 3 beams could not be concentric, they were
closely-spaced parallel beams.____
I forget what tool we used once to measure the radiation from the
front of a CRT, but it wasn't much. In fact, it was almost
undetectable once you got more than an inch away.____
____
bp____
<part15sbs{at}gmail{dot}com>____
____
On 7/21/2019 8:36 AM, Chuck McCown wrote:____
I got a thumb into the HV on a TV once. Felt like a dull
twisted awl that was red hot being jabbed into my thumb. Not a
feeling of shock at all.____
____
Yep, once I discharged my first CRT I got over the fear and then
kinda looked forward to doing it. I don’t remember triplers,
seems like there was an HV rectifier tube. Maybe it was just a
chopper that fed the triplers or stick rectifier. I always
presumed the tube did the job. Maybe the tube just made the
horizontal scan?____
____
*From:*Ken Hohhof ____
*Sent:*Sunday, July 21, 2019 9:23 AM____
*To:*'AnimalFarm Microwave Users Group' ____
*Subject:*Re: [AFMUG] OT 50 years ago____
____
I think it could be as high as 30 KV. Hard to believe we all
had these things in our living rooms. Between the high voltage,
the X-rays (stopped by thick leaded glass at the front), and a
big glass tube with a vacuum inside and a fragile neck.____
____
I worked a couple years in the 70’s for Warwick Electronics,
which made TVs for Sears and Kmart. Before you worked on a set,
you had to discharge the CRT which was like a big capacitor and
would hold the charge for awhile. The engineers and techs there
would break off a length of solder, hold one end against the
chassis, and hold the other end against a big flat bladed
screwdriver which they would shove under the anode cap with a
Zap sound. I was not brave enough to do it that way, I would at
least use a wire with alligator clips at each end.____
____
BTW, the lingering charge problem was worse when they replaced
went to triplers instead of stick rectifiers. A voltage tripler
is basically a bunch of capacitors and diodes.____
____
We also had an electrostatic voltmeter to measure second anode
voltage. It was on a rollaround cart and had a vacuum inside
and the voltage was measured by the deflection of a needle based
on the electrostatic repulsion of two plates. Another
capacitor, and it could hold a charge for days. It was referred
to as “the dog” because it was the size and shape of a medium
size dog, had a snout where the high voltage probe went in, and
it would bite you if you weren’t careful.____
____
We had a high voltage engineer who died of electrocution. Not
at work, but at home, from his ham radio transmitter. Heart
stopped, wife called 911, but they didn’t get there in time.
Live by the sword, die by the sword.____
____
I was told that most serious accidents from CRTs come not from
the shock itself, but the shock would cause your arm to jump and
break the neck off the CRT and you would get cut by the glass.____
____
____
*From:*AF mailto:[email protected] *On Behalf Of *Bill Prince
*Sent:* Sunday, July 21, 2019 8:56 AM
*To:* [email protected]
*Subject:* Re: [AFMUG] OT 50 years ago____
____
I don't recall what the voltage was on black and white TVs.
Probably somewhere in the range of 10K - 15K volts. Early color
TVs could be as high as 25K volts. Aquadag is the term for the
metal coating on the inside of CRTs. High positive voltage is
applied to it to bleed off all the electrons being shot at the
screen. In those days we called the high voltage circuit and
whatever voltage as just "aquadag".____
____
bp____
<part15sbs{at}gmail{dot}com>____
____
On 7/20/2019 7:38 PM, Chuck McCown wrote:____
Yeahbut, they all did it, especially the color TVs. I
presume aquadag is autocorrect for Anode. ____
____
*From:*Bill Prince ____
*Sent:*Saturday, July 20, 2019 5:18 PM____
*To:*[email protected] ____
*Subject:*Re: [AFMUG] OT 50 years ago____
____
The aquadag HV on early TVs was a common source of problems.
Get a little dust on the top of the TV's cathode tube, and
you'd get these periodic "snap!" sounds when it would
discharge through the dust.____
bp____
<part15sbs{at}gmail{dot}com>____
____
On 7/20/2019 12:49 PM, [email protected] wrote:____
It was TV of the mind. I didn’t want to risk going into
the house on the off chance that the B&W TV would
actually work. It was terribly flakey. Had some kind
of HV problem where it would go very dark after a few
minutes. ____
____
So I stuck to the radio. ____
____
*From:*Bill Prince ____
*Sent:*Saturday, July 20, 2019 1:16 PM____
*To:*AnimalFarm Microwave Users Group ____
*Subject:*Re: [AFMUG] OT 50 years ago____
____
We had a Buick too, but ours didn't have a TV, so we had
to watch it on our black and white TV in the house. ____
____
--____
bp____
part15sbs{at}gmail{dot}com____
____
____
On Sat, Jul 20, 2019 at 8:53 AM Chuck McCown
<[email protected]> wrote:____
I watched the moon landing on the radio of a 1965
Buick Special. ____
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