And EICO
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> On Jul 21, 2019, at 3:50 PM, Bill Prince <part15...@gmail.com> wrote:
>
> I did a few Heathkit projects.
>
>
>
> bp
> <part15sbs{at}gmail{dot}com>
>
>> On 7/21/2019 12:22 PM, ch...@wbmfg.com 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 <af-boun...@af.afmug.com> On Behalf Of Chuck McCown
>> Sent: Sunday, July 21, 2019 11:12 AM
>> To: AnimalFarm Microwave Users Group <af@af.afmug.com>
>> 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: af@af.afmug.com
>> 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:af-boun...@af.afmug.com On Behalf Of Bill Prince
>> Sent: Sunday, July 21, 2019 8:56 AM
>> To: af@af.afmug.com
>> 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: af@af.afmug.com
>> 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, ch...@wbmfg.com 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 <ch...@wbmfg.com> wrote:
>> I watched the moon landing on the radio of a 1965 Buick Special.
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