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 Post subject: BK precision 1077b television analyst fly back!!
PostPosted: Jun Fri 21, 2013 2:18 am 
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I plugged this thing up and a resister started smoking so I decided pull the tubes and look for parts but then I got to thinking ,
that thing over in the corner looks A lot like what my old man used to call a fly back,
if so, I guess I charged the thing when I powered it up,
my question is how long before I can unplug the tubes hooked to the thing safely with out (flying back) across the room,lol


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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Jun Fri 21, 2013 10:12 am 
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The flyback transformer itself is not the part to that will store a charge, but the CRT tube can hold a charge and any highvoltage capacitor in that area. The HV rectifier tube may connect to such capacitors.
Your question about 'length of time' is perfectly reasonable, if we ASSUME that all parts are good. But, if there is a failed bleader resistor, ..... then no 'normal' time applies.
Some people use a test bleeder resistor with a ground lead and a stick for a long handle to poke around with so the resistor takes the discharge to the ground, instead of your finger.

IIRC 2-5 Megohms and a watt or 2 would do for the resistor.

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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Jun Fri 21, 2013 11:39 pm 
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Location: Keizer, Or
The part you are pointing to in the second picture is the high voltage rectifier tube. The flyback is the next part to it's right. A black colored coil (transformer). Coils don't hold a charge. Discharge the CRT anode to ground through a resistor.


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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Jun Sun 23, 2013 11:27 pm 
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Joined: Jan Thu 01, 1970 1:00 am
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Location: Phoenix, Arizona
The 1077 has a flyback and is essentially a TV set.

You will need to understand the circuit, but to discharge the HV just slip a small screwdriver under the cap on the picture tube with a clip lead to ground, in standby or off.

The tubes are series string but run on the secondary of the transformer, If one is removed they all lose filament.

In standby B+ is turned off.

There is a guy on this forum who has parts for these and I got a spare set of tubes for my two at Antique Electronic Supply.

There are several designs of the 1077b including one version that does a divide by 12 using two CMOS chips and no H-hold control. I mention the H-hold situation because sometimes the H output will draw heavy current in a lack of drive situation.

There are two H-out tubes, one has an open plate connection so you can substitute the 1077 for an entire sweep section.

These are new enough that the capacitors are usually OK.

Never found one with a dead CRT.

Ask any question, we have discussed these and the older versions at length on this forum.

Jim

I also re-solder all the PC board connections on the bottom.

Beyond that I swear by these and use mine all the time.


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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Jan Mon 20, 2020 5:30 pm 
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Without a CRT what would one use it for?


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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Jan Mon 20, 2020 6:38 pm 
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Location: Dallas, TX
Fatrask1 wrote:
Without a CRT what would one use it for?

The 1077 is used to provide a NTSC test signals to TV receivers. I assume by CRT you mean a NTSC TV receiver or monitor. CRT is an abbreviation of "cathode ray tube".

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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Jan Fri 24, 2020 12:08 am 
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Location: Southwestern,Ontario Canada
You need to recap your 1077b. There is a 220 ohm, 7 watt power resistor under the chassis in that area. If the filter caps are shot, it will pull a lot of current through it, causing your "smoke ". If you look at it, it will probably be cracked.
Tony


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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Jan Fri 24, 2020 12:28 am 
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Joined: Jan Thu 01, 1970 1:00 am
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Location: Phoenix, Arizona
This is an old post, but so am I.

Are you saying that you have a B&K 1077 and it is missing the CRT (picture tube) ?

The 1077 is a test signal generator that will produce a test pattern that can be tuned in on an Analog (NTSC) TV.

They are quite usefull when servicing old TV sets as all analog TV has gone to the afterlife.

The CRT used in these produces Ultra Violet light and not white light.

They used to come around on ebay for 25 bucks.

I keep a couple around so I don't have to dig up a converter box.

Jim


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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Mar Thu 26, 2020 11:43 pm 
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I have one of those seems to work well but I don't have anything to check it on. Any ideas what one could do with it?


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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Mar Fri 27, 2020 12:46 am 
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Joined: Nov Wed 30, 2016 7:35 pm
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Location: Sunbury, Ohio 43074
There's little you can do with one of these unless you fix old TV's. There's really no way other than an oscilloscope to tell if it's actually working, unless you have a working TV to hook it to.

It's basically a "cheater" version of a TV transmitter, generating both a complete NTSC signal by using its own CRT and Photo tube to basically "transmit" via its output cable, the picture of the test slide you insert over the CRT inside. It also generates a whole host of useful signals to help in troubleshooting a TV on the bench.

Other than just looking at it and twirling a few knobs, it's only real use is as a TV repair tool. At least, to me. :-)

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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Mar Fri 27, 2020 4:03 am 
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Joined: Jan Thu 01, 1970 1:00 am
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Location: Phoenix, Arizona
This is an ancient thread but . . . . .

If you mess with old TV sets as I do, you will find one of these highly useful in that there is no analog TV being broadcast on the air anymore so it is a quick way to get a signal to an old TV that is not digital.

They show up on ebay frequently and are cheap except for shipping.

If you lift the lid you will know immediatly if it is working by the UV glow.

I also collect early radios and about the only way to test one of those is to build an AM bootleg Tx as they are also about all gone from the airwaves :)

Jim


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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Apr Wed 01, 2020 11:24 pm 
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Joined: Dec Sat 23, 2006 5:49 pm
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Location: Warsaw, Missouri
I was recently given a 1077B. It's totally dead, complete with blown fuse. The filter caps appear to be shorted. There are about 10 or 11 electrolytic caps in the chassis. It's the model without the IC's. The tube codes are 1969. I have no leads, only one transparency. No manual. I do have a schematic. I'm kinda looking forward to tinkering with this thing. I've wanted one for eons. I understand that it is prudent to recap one of these before you use it.

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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Apr Thu 02, 2020 1:22 am 
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Joined: Nov Wed 30, 2016 7:35 pm
Posts: 6909
Location: Sunbury, Ohio 43074
Filter caps do not generally short out, as a rule. But if they are old electrolytics, I'd replace them anyway.

Good luck. I used one of these when I was in TV service.... made things much easier and faster.

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Preserving the hist. of electronics, one boat anchor at a time! :)
https://www.bbtvtestequipment.com


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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Apr Thu 02, 2020 3:06 am 
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Joined: Dec Sat 23, 2006 5:49 pm
Posts: 1370
Location: Warsaw, Missouri
The Analyzer I have has a short in B+. When I disconnect the filter caps, the short disappears. The 80uf cap is the one that is shorted. The filter cap can has been leaking something. There is corrosion around the base of the can. I'll start with replacing the caps, then I'll replace the fuse and test the filament circuit (standby) then the B+ circuit. This will get me started. I'm sure there may be something else. Thanks.

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 Post subject: Re: BK precision 1077b television analyst fly back!!
PostPosted: Apr Sat 04, 2020 7:23 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 1668
Location: Phoenix, Arizona
If it is one of those four lug can type electrolytic s, those are being made again using old Mallory equipment in some values that may cover your need.

AES is the dealer.

Jim


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