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 Anyone got an AWA 4KA chassis lying around?
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 Return to top of page · Post #: 1 · Written at 9:36:09 PM on 24 June 2021.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 2088

Apparently these are like rocking horse manure in the UK. Just manure to us!

I guy on the UK forum is looking for a Thorn 4000, aka 4KA here....


 
 Return to top of page · Post #: 2 · Written at 9:42:26 PM on 25 August 2021.
Shaneh's Gravatar
 Location: Creswick, VIC
 Member since 6 August 2015
 Member #: 1783
 Postcount: 18

There are some out there.
I have a few AWA and Thorn sets but tightly stored away at the moment not able to part with anything at this stage and the UK is a long way to send to.
Still after a thorn 3500 set if anyone is keen to trade/sell.


 
 Return to top of page · Post #: 3 · Written at 10:07:51 PM on 25 August 2021.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 2088

I doubt the shipping cost would be a problem for this guy.


 
 Return to top of page · Post #: 4 · Written at 8:27:05 PM on 26 August 2021.
BringBackTheValve's Gravatar
 Location: Linton, VIC
 Member since 30 December 2016
 Member #: 2028
 Postcount: 352

Only one good thing about 4KA's - their cabinet.
Splendid furniture pieces. Chuck out the guts and just admire the cabinet.


 
 Return to top of page · Post #: 5 · Written at 11:16:37 AM on 29 August 2021.
Shaneh's Gravatar
 Location: Creswick, VIC
 Member since 6 August 2015
 Member #: 1783
 Postcount: 18

Hi Ian. What was the web address. I’ll send him a message.


 
 Return to top of page · Post #: 6 · Written at 1:14:03 PM on 29 August 2021.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 2088

https://www.radios-tv.co.uk/user/chris/?profiletab=fep-um

I sent him your email address and a link to this post.


 
 Return to top of page · Post #: 7 · Written at 8:22:25 PM on 2 September 2021.
Shaneh's Gravatar
 Location: Creswick, VIC
 Member since 6 August 2015
 Member #: 1783
 Postcount: 18

Thanks Ian.


 
 Return to top of page · Post #: 8 · Written at 2:02:37 PM on 22 November 2021.
Keith Walters's avatar
 Location: Sydney, NSW
 Member since 16 January 2008
 Member #: 219
 Postcount: 58

I worked for AWA/Thorn when those things were new and the reliability was shocking even then.
I'd be very surprised to see one working now.
The 4000 chassis made extensive use of thick-film modules which really didn't achieve anything but were hopelessly unreliable, and the company that made them soon went out of business.
The final production actually had the modules replaced by standard PC boards, which were much more reliable, but had terrible thermal drift problems. I actually devised some modifications using thermal compensating diodes that made them work pretty well, but by then AWA had pulled the Thorn connection and went to Mitsubishi.
I guess if you found a 4KA with those modules in it, you might have a chance at getting it going, but if it has the epoxy modules, pretty much "Buckley's".
A 3504 (Thorn 90° 3500 chassis) would be a much better bet.
I'd like to get one of those myself, as I know all their common faults.


 
 Return to top of page · Post #: 9 · Written at 10:21:30 PM on 22 November 2021.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 2088

Hi Keith

Our friend in the UK has since found two 4000's.

One of them is missing its vertical module.

Thermal drift problem doesn't surprise me, the vertical circuit is a classic example of a very naive design.

Did you by any chance keep the documentation for the TF replacements?


 
 Return to top of page · Post #: 10 · Written at 3:03:45 PM on 23 November 2021.
Keith Walters's avatar
 Location: Sydney, NSW
 Member since 16 January 2008
 Member #: 219
 Postcount: 58

No, but I remember the 4KA circuits used to show the internal circuitry of the modules.
I think they even showed the resistor values.


 
 Return to top of page · Post #: 11 · Written at 7:43:26 PM on 3 December 2021.
BringBackTheValve's Gravatar
 Location: Linton, VIC
 Member since 30 December 2016
 Member #: 2028
 Postcount: 352

To Keith and Ian,

I have just read your posts regarding thermal drift in 4KA's, which triggered an unfortunate flashback for me as a newly qualified TV tech.

I happened to come across a 4KA with drifting grey scale and using the hair dryer/can of freeze method determined the fault to be a module. My employers secured a new module but after replacing the "crook module" the fault returned, resulting in an embarrassing call-back.

The customer wasn't very nice, (read angry) and I found myself copping flak from both ends as I struggled to determine the cause of the drift. Again I used the heat/ice method and the new module was the suspect. My bosses were not convinced and refused to procure another.

After continued pressure from customer and employer alike, in desperation I declared a "crook" picture tube. Thankfully the repair did not go ahead. Now, four decades later as I read your comments I wonder if my diagnostics method of blasting these modules with heat and ice may have contributed to that debacle?


 
 Return to top of page · Post #: 12 · Written at 5:48:55 PM on 5 December 2021.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 2088

The company I worked for in the 60's and 70's used to do warranty service on new colour TVs. The retailer would buy a 3 months service contract from us and they could then wipe their hands of any service responsibility. This was how it was done by most retailers, especially the large discount chains.

The 4KA was so bad that we were losing money on the deal so after a while we upped the price on the contract for this model, making AWA very annoyed of course.


 
 Return to top of page · Post #: 13 · Written at 8:45:22 PM on 5 December 2021.
BringBackTheValve's Gravatar
 Location: Linton, VIC
 Member since 30 December 2016
 Member #: 2028
 Postcount: 352

My employers were service agents for several brands, but not AWA. Most annoying then that we were called to repair those abominations and not the agent.

If I was into conspiracy theories I would say the guys who were AWA repair agents shoved those monsters onto us. (Cannot blame them)

I'm glad AWA were annoyed----they deserved it for unleashing the 4KA into Oz. The term 'dumping' can be interchanged with 'unleashing'.

I still recall moments of bliss upon entering customers homes and seeing Jap AWA's decorating their lounge rooms.


 
 Return to top of page · Post #: 14 · Written at 9:44:09 PM on 9 December 2021.
Shaneh's Gravatar
 Location: Creswick, VIC
 Member since 6 August 2015
 Member #: 1783
 Postcount: 18

My parents bought a Thorn AK4 set second hand in 1977.
It went for years with no problems. They replaced it in 1986 with a new set as they needed one with UHF.
Dad used it in his shed for a few years after that until one day when it finally died when water from the leaking roof got into it.


 
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