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#1
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New here from New Hampshire USA
Hi all!
I'm relatively new to tvs, coming from a hobbyist background in audio gear and loudspeaker building/repair/restoration. My 14year old son is really into vintage tech. For Christmas we got him a couple B&W tvs from the fifties: a Motorola 14P51 and RCA Victor 14PD8053. We really love the beautiful styling of these little tvs. We're restoring them together and learning as we go. It's been really exciting so far. Glad to be a member! |
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#2
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Welcome to videokarma. Good to see parents getting their kids interesting in the hobby.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
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#3
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![]() (Sorry, couldn't resist.) Welcome to both of you! |
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#4
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Welcome to the site.A lot of knowledgeable and helpful members here. RonL
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Source of free vintage Canadian tv service info.Caretaker of various 1920 to 70s radios,a Farnsworth 651p tv,a RCA Ctc5 and a few 50s tvs. Last edited by ronl; 01-11-2026 at 12:49 AM. |
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#5
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Welcome to VK!
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Ham shack...AM side: Knight-Kit T-60, RME-45 Vintage SSB side: National 200 Modern SSB: Kenwood TS-180S MFJ tuner, 130' dipole |
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#6
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Welcome!
Your son has great parents! My hobby was a nightmare to my parents......... ![]() ![]() You both will find hear the right help! ![]() Regards, TV-collector
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Scotty, beam me up, there is no more 4/3 Television and AM radio in Germany! |
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#7
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Thanks for the warm welcome
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Thank you electronjohn! Glad to be here! Thank you TV-collector! Based on my reaction when surprise! he brought his first hot-chassis radio home (loose backing and exposed metal hardware!), i can imagine your parents' anxiety with this stuff! |
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#8
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With most TVs the 6-25KV on the second anode of the CRT is generated by a flyback and can only supply around 2mA tops. Voltage isn't what injures so much as current. It typically takes 30mA to kill someone who doesn't have a heart condition. CRTs have a built-in capacitor that can store charge at operating voltage... I've been shocked by it more times than I can count. The charge and voltage are roughly what you can get from a mean static shock shuffling your feet on carpet (the carpet can sometimes get you above 30KV). Often reflexes making your arm slam into things are more dangerous than the shock it's self. Where CRT HV is dangerous is in pre-war TVs and a small handful of late 40s TVs that use a 60Hz transformer to make around 6KV HV directly from wall outlet voltage...if you are familiar with microwave oven transformers (basically the same thing) and the leathal hazard they pose (they can easily generate enough current to kill) then you know to never touch anything associated with them if it is plugged in...(Luckily sets that use a 60Hz HV transformer are rare even among vintage TVs...I have exactly one such set in my collection of over 100 TVs).
What is deadly in a tube TV is the B+ at roughly 450V at as much as 250mA, the yoke voltages which can be roughly 3KV spikes that can have entire Amps of pulse current behind them. Anything between the horizontal output tube plate and the damper is as bad and will give you a mean RF burn (it'll burn a hole at the point of contact). I've touched a plate connection accidentally at least once and don't want to repeat it. It's good practice to work with one hand behind your back when working on a powered set and to avoid touching anything grounded with any part of your body. Birds are able to sit on 11KV power lines without getting shocked because they aren't touching anything grounded. Having clip leads so you can clip your DMM to a point of interest with the power off then turn the TV on without touching stuff is a good practice for beginners. When the set is off if you want to discharge the HV for servicing get a 1M-10M resistor, connect one end to the metal shaft of a screwdriver with a well insulated handle, connect the other end of the resistor to the CRTs aquadag ground (usually there's a spring or bracket it connects to that's a good connection point and slip the screw driver blade under the HV suction cup connection on the CRT until you hit metal and hold it there for a good 15 seconds. You can skip the resistor and ground the screwdriver blade directly but it'll be more prone to dielectric voltage bounce back. Using a HV meter rated high enough to measure the TVs HV is the safest way to discharge it and let's you see the voltage while doing so. It's often worth redischarging the tube a second time before touching it if it's sat a minute since discharged and you're about to touch it... I've been bit by bounce back far more than by the actual live HV.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
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