My Bush TV43 restoration.

[audion_1908]

Originally Posted by Heatercathodeshort

You don't need to get the valve tester working, believe me. It will not help you with your restoration. [They are only used by valve dealers these days] I have a TMK multimeter that I used to carry in my service kit. It works OK but the 15v battery for the high ohms range is low but I think you can get these off the Internet.
You are most welcome to it foc and it's easy to use. PM me if you think you would like it with your details. John.

Thanks for the very generous offer of the TMK multimeter but I have found an old working analog multimeter in a box I had forgotten about.

[audion_1908]

Originally Posted by freya2871

Just to reiterate what John said.
You are kind of taking the fun out of the restoration, if you test the valves first you do so you might feel that they are little on the low side maybe and go and buy a new valve which means you miss the effect a low valve might have. Also most valves that test low from a TV will in fact work perfectly.

I speak from experience as this is what I wanted to do with my first set, in fact when the set was on it told me what needed doing with a nice purple glow from the EHT rectifier and the output valve It won't damage anything.

Steve

I know that most of the valves can be low and the tv work ok, and I have a load of spare tv valves from an old project, and the wax caps needed replacing same with the rubber wire, some was so bare I dont know what color they where! that would have coursed problems.

[audion_1908]

Originally Posted by mark pirate

John and Steve are spot on.

You will also learn a lot more if replacing one cap at a time, and noting the results.

Blanket replacement of parts does not teach you anything, and you may end up chasing your tail trying to sort out the man made faults by fitting the wrong part or by disturbing other components and wiring.

I hope you take up Johns generous offer of the meter, don't rely on your faulty Avo.

Mark

the only thing that I am giving a blanket replacement are the wax and electrolytic caps, as they will corse problems and need to go as the set has been stored damp for a long time, and I am not testing all the parts as its too much work, and I will still have a lot of fault finding to do,

[audion_1908]

Originally Posted by freya2871

Just to reiterate what John said.
You are kind of taking the fun out of the restoration, if you test the valves first you do so you might feel that they are little on the low side maybe and go and buy a new valve which means you miss the effect a low valve might have. Also most valves that test low from a TV will in fact work perfectly.

I speak from experience as this is what I wanted to do with my first set, in fact when the set was on it told me what needed doing with a nice purple glow from the EHT rectifier and the output valve It won't damage anything.

Steve

there will still be a lot of fun to be had getting the tv in fully working but now maybe not to much smoke!

and I mixed the posts on the avo meter and the valve tester, the avo now only has a cooked resister (wire on circuit board), and a missing one and it was the valve tester with the control going round with no easy way to get the pointer aligned right.

[Sean Williams]

The problem with fitting new replacement caps all over the set is the very real chance of either fitting a wrong component, or fitting it in the wrong place - it's not so bad in a radio - you can hear the results, but on a TV that shows no sign of working you could screw everything up completely in the rf and timebase section, and be none the wiser - a repair that might only have taken a couple of hours then becomes weeks of hard work.

When the set gets to that sort of state it becomes very difficult for anyone to hazard a guess as to where the faults are - a lot of the advice given here is by time served engineers, that worked on these sets on a daily basis, and will have built up extensive knowledge of "Stock Faults"

I recently repaired a Bush Tv24 - I only needed my Avo meter, a couple of screwdrivers and other hand tools, some odd wire with croc clips and a diagram to work from - first light took about 6 capacitors and resetting the ion trap.

I hope you manage to get this set back together and working.

Sean

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I am close to plugging it in!!

I have replaced all the rotten rubber wire, and all the wax and electrolytic capacitors except for one thats still in the post.
I have fitted two type x2 capacitors, and I was poking around with a dvm and found the on/off switch was not working > 2m ohms, I opened it up and cleaned up the corrosion and its fine now, I will probably find I have to clean all the pots, its a shame the TV was not stored in a nice dry attic.
I have also cleaned the worst of the corrosion from the valve pins and sockets,
I also have a power lead with RCD as my flat dose not have one, I have payed for a graphics card for mythtv, it just has to arrive!

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I am worried about the ECL80 socket as its missing some parts!! two of the pins are only held on one side!! I may have to find a new ceramic base and replace it, a lot of work but I will probably have to do it.
I had to replace the EY51 as the old one was cracked, but it could be possible to wire it round the wrong way as its indirectly heated but tied to the filament inside?
also how do you disconnect the EHT lead from the CRT? I had to cut the EHT lead to get the chassis out, I was going to replace it but cant find a spare, so I am using silicone self fusing repair tape thats good to 8KV per layer, so I am using 2 layers on the EHT lead and 4 layers where it exits the steel safety shield as the grommet is badly perished, as I dont want to risk my lopt.

I found my TVs age from the old electrolytic capacitors, September 1954!!!

so all I have to do is fit one capacitor, look for mistakes in my work, and rewire the CRT crt deflection coils, I missed a bit of rubber wire, lol
and test some of the cracked ceramic tube capacitors, and build a computer with mythtv for my score of 405 line tv
I not got the valve tester working, but I have saved all the old wax and electrolytic capacitors as someone may want to stuff them!

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I also need to thoroughly read the three data sheets I have in my Bush TV43

I have also found 3 large isolating transformers I got for free years ago, I think they are 200va so fine to run my TV on when fixed.

[Freya]

Could you take a few pics of these cracked ceramic type capacitors ?. Not heard you mention the VHF modulator to use with the pc, did you sort one.

[Heatercathodeshort]

The EY51 can be connected either way. It makes no difference as you are dealing with around 12kv at 100 microamp. Two types of EHT connector have been employed. The earliest one is simply like a large valve top cap. The clip can be rather stiff but if sprayed with WD40 and left for a couple of hours, a gentle twist should then free it.
The second type is what is known as a 'cavity connector' type CT8. This is a small sprung button that fits into a cavity in a metal cavity in the glass. The bit with the EHT lead soldered on needs to be gently prized out after application of WD40. If you need a picture illustrating the bits, I can upload one.
In an ideal World the EHT lead should be replaced with the inner SOLID conductor from old style co-ax cable.

[audion_1908]

Originally Posted by freya2871

Could you take a few pics of these cracked ceramic type capacitors ?. Not heard you mention the VHF modulator to use with the pc, did you sort one.

I have not started the rf modulator yet

[audion_1908]

Originally Posted by Heatercathodeshort

The EY51 can be connected either way. It makes no difference as you are dealing with around 12kv at 100 microamp. Two types of EHT connector have been employed. The earliest one is simply like a large valve top cap. The clip can be rather stiff but if sprayed with WD40 and left for a couple of hours, a gentle twist should then free it.
The second type is what is known as a 'cavity connector' type CT8. This is a small sprung button that fits into a cavity in a metal cavity in the glass. The bit with the EHT lead soldered on needs to be gently prized out after application of WD40. If you need a picture illustrating the bits, I can upload one.
In an ideal World the EHT lead should be replaced with the inner SOLID conductor from old style co-ax cable.

It is good to know that it makes no difference if the EY51 is connected either way round, and the replacement EY51 I got cheaply and was sold as nos in box so should be good, it looked clean with long wires.

I think I have a cavity connecter but the EHT wire is a bit frayed were it is soldered on, I dont have any WD40 I will try some contact cleaner till I get some, the EHT lead is not perished just cut by me, will it be ok soldered back together and taped with silicone self fusing repair tape that's good to 8KV per layer, and I will use 4 layers to be safe?

on the old style co-ax cable do you mean solid copper wire or insulation as I have some old 10base2 network co-ax cable somewhere that I think has solid insulation and stranded copper inner wire, but its used and probably 20 years old, where can I get EHT cable if I need one?

I could do with some pictures of the cavity connector, as I dont want to damage the CRT or me!

I will be working on replacing the last rubber wire on the deflection coils tonight.

any pics wanted?

[audion_1908]

Originally Posted by freya2871

Could you take a few pics of these cracked ceramic type capacitors ?. Not heard you mention the VHF modulator to use with the pc, did you sort one.

here are some pics of the cracked ceramic type capacitors, I have looks into these strange capacitors as I have never seen any like them before, they are called ceramic tube capacitors?

I will test some of the dodgy looking ones, and if good leave them alone, but I will measure the current thru each valve to test for cap leakage, when I power the TV

[audion_1908]

more possibly dodgy caps.

I am a bit worried that damp may have got into the ceramic caps?

the last pic is of two replacements for 2 crispy ceramic caps, they are not critical as they only decouple the heater chain, but may have cooked some of the filaments,

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This is the damaged ceramic socket for the ECL80 and it is missing part on the contacts for two valve pins, I don't know how much of a problem this will be? but it will be a real pain to replace the ceramic valve socket
I did find a valve shield for the ECL80 on the plus side.

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This is the tv RF board after cleaning and with all the right valves fitted, (I do have the valve shields) the antenna input had a cap to the steel case for ground, I tried to find a type y the right size but had to use a 15000v dc cap instead, this should do the job and keep the 230v off the antenna socket.

None of the valves have been tested, 13 are from my collection 5 came with the tv and I payed for a NOS ECL80 and NOS EY51 as I did not have them in my collection, there was no real difference in price from a NOS ECL80 and EY51 to an untested pulls? I retired the old EY51 as it was cracked into the base seal and has lost a bit of glass, it could be ok but I don't trust it, I still have it with the old caps.

[audion_1908]

the speaker used to have a small connecter board so you could take the main boards out to work on, but it is damaged and has been bodged before, where can I get a similar type of connecter, I really don't want to use a modern terminal block I am getting really close to testing the tv!

strangely all the rubber wire was so perished it crumbled when you moved it, except the speaker wire at the front that's fine? the back of the tv must have been facing a window and the sun got to all the other rubber wire or something?

I have replaced the perished rubber wire to the deflection coils, the old wire was so bad even the cotton cover was crumbly and could not be saved the new wire is thinner but I dubbed it up so it should be ok, what is the peak current threw the deflection coils?

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This is all the old capacitors from the tv, and the red one was an extra one used to ground the antenna socket, and was very badly fitted?
its labeled R.S. 50 +-1% and without a voltage rating on it its not safe to use, to isolate the antenna socket.

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CRT and case cleaning
The dust had formed a crust on the CRT and inside parts of the wooden tv case, it also had bits of silver foil in it? I am guessing it was crisp packet, long dead, I used Wire glue to replace the conductive coating on the CRT where the old had flaked or rubbed off ,strange stuff wire glue?

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MythTV
The only card that has been used to output 405 lines is PCI or AGP, I got the AGP one as it was much cheaper, but I will have to go to storage to pickup an old computer to use with MythTV as none of the other pc's have an AGP slot.