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Grabbin' Stuff Inside a BTA-250 While It's On?




 
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Author Topic: Grabbin' Stuff Inside a BTA-250 While It's On?  (Read 657 times)
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WBear2GCR
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Brrrr- it's cold in the shack! Fire up the BIG RIG


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« on: March 27, 2017, 11:52:06 PM »


Maybe it's a Gates... didn't sit for the whole thing, but I didn't catch where he put a shorting stick to anything...
perhaps it's there. But I ain't GRABBIN' NUTHIN' in there with the power on! How about you??

https://www.youtube.com/watch?v=ZzpVhCL5aPg
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_-_- bear WB2GCR                   http://www.bearlabs.com
W9BHI
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« Reply #1 on: March 28, 2017, 11:36:13 AM »

I'm sure the plate supplies were off when he was doing this video.
I sometimes make minor adjustments to my Gates BC-1G with the filaments on.
Some people think that if you open up the front door on one of these while it's running, a demon will jump out at you and grab you by the throat.
You have to have the utmost respect for these transmitters but if you are afraid of them then you shouldn't own one.

Don W9BHI
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WBear2GCR
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« Reply #2 on: March 28, 2017, 01:39:13 PM »


Ever left a burner on an electric stove on?
I sure have.
Did I mention I DO NOT LIKE Electric Stoves!!

Fear? Yeah, fear of being toast? Yup. Gonna take precautions, I am.
Double safety for this wimp.
I gonna tie that HV to GROUND before I stick my hands into anything with HV.
Even in the 200vdc and up range.

That's just me.
Don't like those "bites" at all. No I do not, nope. Cheesy
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_-_- bear WB2GCR                   http://www.bearlabs.com
W3RSW
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Rick & "Roosevelt"


« Reply #3 on: March 29, 2017, 08:27:41 AM »

Really ?  --you never even built a Heathkit audio amp back in the day and checked resistances, then voltages around the circuit for curiosity, satisfaction and experience?  Grin

You never learned caution when placing your VTVM probe to adjacent pins on a live circuit?

You never worked on typical RF And AF circuits up to 750 VDC or so?
Yeah we all got extra cautious when specs called for HV probes, voltages over the typical 1kv limit of common test apparatus and stuff,  but 250 volts on your HB 6F6 xtal,, single stage novice rig?

You typical tv serviceman knew that the odds of a forgotten, shorted medium voltage circuit would cost more money than not using Voltage respect measurement procedures . His respect for the HV cage, CRT HV, etc. was much greater of course.

Or maybe you did get burned a couple of times and have since become permanently really cautious .  That I can respect.  Grin.
Probably we all should start being more cautious as we age.
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RICK  *W3RSW*
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« Reply #4 on: March 29, 2017, 11:33:20 AM »

The guy thinks heís ďMr. ScienceĒ and spends too much time talking about things that he donít know. Thatís the problem with the internet is that regardless of how much you think you know there is always a whole bunch of people who know more and done more then you have and you have to expect to hear from them when you present yourself as an expert and just from the little bit of this clip I can tell Mr. Science never been in broadcasting, at least as an engineer. But maybe I am just worked up because his way too long video of a broadcast transmitter has ten times the hits as my video. Perhaps my problem is that I did not have a microphone in my shots? Go figure. Anyway in an attempt to try to get a couple more hits on my YouTube account you can see my video at:

https://www.youtube.com/watch?v=LETZZRauMbQ

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WA7BBI
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« Reply #5 on: March 29, 2017, 11:51:21 AM »

I don't understand the problem here. Paul clearly showed that the only power applied to the transmitter was the 10 volt filament line. He even tested the interlock system to assure there was no HV present, before he entered the back of the rig. During all of his videos he cautions about lethal voltages. My only problem with Paul is his pronunciation of soldering.
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K0SF
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« Reply #6 on: March 29, 2017, 12:47:14 PM »

There's no problem with low voltage.  Sometimes you don't have a choice and it is the most practical way to make a measurement such as voltage on a filament with a tube present.  I have done it numerous times in my 20V-3, but I have an extra manual interlock on the plate enable that I double check when I go inside.

The most present threat is the 220 VAC door interlock which I stay away from.

Thinking and awareness are your best defense.

Steve, K0SF
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KA3EKH
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« Reply #7 on: March 29, 2017, 02:04:25 PM »

Went back and watched it again, Ok, so Mr. Science is smart and all that but he is not a broadcast engineer. He tone and mannerism lead you to assume he is an authority but he makes fundamental mistakes about things like the transmitters were always located away from the station and operators. It was not until the FCC deregulated AM broadcasting seventies that all AM transmitters had to be in direct sight of the control operator, thatís why so many stations had windows from the studios to the transmitter so you would be able to see it, and back when that transmitter was built that was a big deal. Then in the discussion of the RF line current he discounts its importance and anyone who has ever been involved with AM broadcasting knows how big a deal your base current is. Back when you had to keep logs that was one of the parameters you had to log every three hours and one of the things the FCC looked at and with all the time spent talking about the meters not a word about using them to determine indirect power? But all this is just splitting hairs compared to the big deal, one of the first things you learn in radio or TV is the shorting stick rule. Never touch or go into any part of a transmitter without first checking it is safe by touching with the ground stick. The interlocks both on the control circuit and the main safety interlock that shorts the HV supply are there for your protection but still its basic safety to check any components for the possibility of a stray charge or sometimes interlock failure. Also to step inside a transmitter when you donít have to be is just stupid. Most if not all the power supplies are 220 volt feed and many will still have primary potential on one side of the circuit and then when the filament is on and you also have the issues of bias supplies that are active or any of the active stages in the exciter or IPA.
I donít know why, maybe itís me and I am just off my meds or something but there is just something about this video that that strikes me odd. Have to give him credit on itís a nice looking clean transmitter and all the work looked first class, and imagine there are any number of people who would view stuff I done on YouTube as pure crap. And did not intend to offend and have to give this guy credit for getting out and doing the stuff, so maybe I should just shut up now and not write any more.

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W3RSW
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Rick & "Roosevelt"


« Reply #8 on: March 30, 2017, 12:24:57 PM »

You just write anything you want.  Stuff experienced by people like you let me learn new things hopefully every day. Reading Lots of things I didn't know or have forgotten can only be for the best. Some of us may interpret things differently and may not agree with some, but we can't make basic comparisons if we don't have references and people like you sharing your experience.
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RICK  *W3RSW*
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« Reply #9 on: March 30, 2017, 01:25:57 PM »

I've watched all of his videos, and I've learned a lot. He may not follow broadcast transmitter protocol, but he is one heck of a technician troubleshooter.
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flintstone mop
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« Reply #10 on: April 02, 2017, 08:01:36 PM »

Really ?  --you never even built a Heathkit audio amp back in the day and checked resistances, then voltages around the circuit for curiosity, satisfaction and experience?  Grin

You never learned caution when placing your VTVM probe to adjacent pins on a live circuit?

You never worked on typical RF And AF circuits up to 750 VDC or so?
Yeah we all got extra cautious when specs called for HV probes, voltages over the typical 1kv limit of common test apparatus and stuff,  but 250 volts on your HB 6F6 xtal,, single stage novice rig?

You typical tv serviceman knew that the odds of a forgotten, shorted medium voltage circuit would cost more money than not using Voltage respect measurement procedures . His respect for the HV cage, CRT HV, etc. was much greater of course.

Or maybe you did get burned a couple of times and have since become permanently really cautious .  That I can respect.  Grin.
Probably we all should start being more cautious as we age.

Rick, me and you and probably a good bunch of us had that wonderful experience to touch electronics and build and repair. Those days are gone forever, unless someone is repairing or restoring an oldie tube transmitter / "vintage' tube amp, etc etc
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Fred KC4MOP
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« Reply #11 on: April 03, 2017, 09:23:40 AM »

Ray - I watched the video about your RCA xmtr.  I enjoyed it and learned a couple things.  I also watched the video about the Gates.  I did not catch his amateur radio call sign if he mentioned it.  I worked on the news side of broadcast radio for several years and came to know a number of very competent engineers who had no formal training.

FYI ... I tried using the AMFone link to your web page but the page didn't come up.
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Brad K4RT
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« Reply #12 on: April 03, 2017, 09:34:57 AM »

I've exchanged e-mail with him - he's up in Canada - his call is  VE7ZWZ - Paul Carlson
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