UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Other Discussions > Homebrew Equipment

Notices

Homebrew Equipment A place to show, design and discuss the weird and wonderful electronic creations from the hands of individual members.

Reply
 
Thread Tools
Old 3rd May 2018, 9:06 pm   #41
Bazz4CQJ
Octode
 
Bazz4CQJ's Avatar
 
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 1,851
Default Re: HT / filament transformers from Aliexpress

Thanks for sharing those results. Looks like that transformer would be fine for most hobbyist use (at least) .

B
__________________
We know there are known unknowns. But there are unknown unknowns ones we don't know we don't know.
Bazz4CQJ is offline   Reply With Quote
Old 3rd May 2018, 9:10 pm   #42
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 16,294
Default Re: HT / filament transformers from Aliexpress

I suspected these would be the results. These things are obviously primarily made for the Chinese companies building valve preamps for the hifi market, and they wouldn't be much use there if they burst into flames after 10 minutes.
paulsherwin is offline   Reply With Quote
Old 3rd May 2018, 10:06 pm   #43
MrBungle
Nonode
 
MrBungle's Avatar
 
Join Date: Jun 2016
Location: London, UK.
Posts: 2,372
Default Re: HT / filament transformers from Aliexpress

Indeed.

Incidentally I bought one of the LCR meters and that did indeed burst into flames after 10 minutes. Well smoked a bit. I think YMMV still. At least it's a promising start.

The plan was to resurrect my never ending VTVM project with this and it looks suitable.
MrBungle is online now   Reply With Quote
Old 14th May 2018, 4:11 pm   #44
MrBungle
Nonode
 
MrBungle's Avatar
 
Join Date: Jun 2016
Location: London, UK.
Posts: 2,372
Default Re: HT / filament transformers from Aliexpress

Well that was disappointing. I finally wired up the second transformer and tests are off because the HT secondary of it is open circuit.

And that concludes the foray into "cheap transformers from Aliexpress".

Conclusion: YMMV.
MrBungle is online now   Reply With Quote
Old 14th May 2018, 5:37 pm   #45
Bazz4CQJ
Octode
 
Bazz4CQJ's Avatar
 
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 1,851
Default Re: HT / filament transformers from Aliexpress

Oh dear . That's a bit discouraging!
__________________
We know there are known unknowns. But there are unknown unknowns ones we don't know we don't know.
Bazz4CQJ is offline   Reply With Quote
Old 15th May 2018, 7:32 am   #46
MrBungle
Nonode
 
MrBungle's Avatar
 
Join Date: Jun 2016
Location: London, UK.
Posts: 2,372
Default Re: HT / filament transformers from Aliexpress

Also way too late to claim it as well!
MrBungle is online now   Reply With Quote
Old 15th May 2018, 8:21 am   #47
merlinmaxwell
Dekatron
 
merlinmaxwell's Avatar
 
Join Date: Jul 2008
Location: Maidenhead, Berkshire, UK.
Posts: 7,447
Default Re: HT / filament transformers from Aliexpress

Quote:
Also way too late to claim it as well!
Worth a try though, mention this thread too, you never know!
__________________
Cats have staff, it's dogs that have owners.
merlinmaxwell is online now   Reply With Quote
Old 15th May 2018, 8:30 am   #48
Bazz4CQJ
Octode
 
Bazz4CQJ's Avatar
 
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 1,851
Default Re: HT / filament transformers from Aliexpress

Yes, definitely would still give it a try. Think it best to grovel rather than get stroppy.

B
__________________
We know there are known unknowns. But there are unknown unknowns ones we don't know we don't know.
Bazz4CQJ is offline   Reply With Quote
Old 15th May 2018, 9:44 am   #49
MrBungle
Nonode
 
MrBungle's Avatar
 
Join Date: Jun 2016
Location: London, UK.
Posts: 2,372
Default Re: HT / filament transformers from Aliexpress

I'll give it a bash and see what happens.
MrBungle is online now   Reply With Quote
Old 5th Jun 2018, 3:57 pm   #50
Bazz4CQJ
Octode
 
Bazz4CQJ's Avatar
 
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 1,851
Default Re: HT / filament transformers from Aliexpress

Have you had any response about the bad transformer?

B
__________________
We know there are known unknowns. But there are unknown unknowns ones we don't know we don't know.
Bazz4CQJ is offline   Reply With Quote
Old 5th Jun 2018, 4:12 pm   #51
MrBungle
Nonode
 
MrBungle's Avatar
 
Join Date: Jun 2016
Location: London, UK.
Posts: 2,372
Default Re: HT / filament transformers from Aliexpress

Being the disorganised person I am, I completely forgot about it to be honest and got distracted with a pile of broken oscilloscopes. They are still all broken
MrBungle is online now   Reply With Quote
Old 5th Jun 2018, 6:10 pm   #52
Bazz4CQJ
Octode
 
Bazz4CQJ's Avatar
 
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 1,851
Default Re: HT / filament transformers from Aliexpress

Oh, don't feel badly about it - we could compete on who is most disorganised

My feeling is that with the "budget" priced stuff, there's not much QA or QC going on, so you could be lucky and get something that is perfect, or luck-out and get something which is useless. You got one of each.

B
__________________
We know there are known unknowns. But there are unknown unknowns ones we don't know we don't know.
Bazz4CQJ is offline   Reply With Quote
Old 7th Jun 2018, 11:57 am   #53
Diabolical Artificer
Dekatron
 
Diabolical Artificer's Avatar
 
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
Posts: 3,368
Default Re: HT / filament transformers from Aliexpress

Might be just a bad solder joint.

Andy.
__________________
Curiosity hasn't killed this cat...so far.
Diabolical Artificer is offline   Reply With Quote
Old 7th Jun 2018, 5:58 pm   #54
MrBungle
Nonode
 
MrBungle's Avatar
 
Join Date: Jun 2016
Location: London, UK.
Posts: 2,372
Default Re: HT / filament transformers from Aliexpress

I peeled the dead one open and there was no solder joint. The terminations were twisted together and then taped and that’s it. Reason it was open because there was still enamel on the winding. Looks like someone forgot to poke it in the solder pot and forgot to QA it. FFS. Binned.

Edit: have been very distracted due to work but have been playing with the LT1073 switching regulator and have managed to get that to deliver 200V at 10mA with an external inductor and MOSFET plus voltage divider from a 12V source. Very nice IC but a little pricey. Now playing with that and E cores.
MrBungle is online now   Reply With Quote
Old 7th Jun 2018, 7:19 pm   #55
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 16,294
Default Re: HT / filament transformers from Aliexpress

Chinese suppliers will usually send replacements for DOA items without too much argument. They are obviously used to the high failure rate.
paulsherwin is offline   Reply With Quote
Old 8th Jun 2018, 6:10 am   #56
joebog1
Heptode
 
joebog1's Avatar
 
Join Date: Jun 2015
Location: Mareeba, North Queensland, Australia
Posts: 613
Default Re: HT / filament transformers from Aliexpress

It is interesting to see that Paul agrees with me on that point!!
In many years of buying Chinese "stuff", I have only had one DOA arrival!.
An air brush, or mini spray gun with gravity feed paint bucket.
I sent them a short 10 second movie of the leaking unit, and hey presto!! I now have two leaking air brushes from China. I am not too upset however, as the sellers were only too happy to replace the said unit. I will lap the "ball end" type fittings with valve grinding paste and will most likely end up with two spray guns.

MrBungle would still be well advised to "give it a go"!!.

FWIW, its the first "bad" deal from China I have had.

Joe
joebog1 is offline   Reply With Quote
Old 8th Jun 2018, 9:23 am   #57
vidjoman
Octode
 
Join Date: Jun 2013
Location: East Sussex, UK.
Posts: 1,854
Default Re: HT / filament transformers from Aliexpress

I think it's wrong to blame Aliexpress as they are a facilitator and not the 'part supplier'.
Aliexpress act as a go-between, take the order and hold your money until you have the goods from the seller and have responded that you are satisfied with them. It is only then that the supplier gets paid. There is a time limit in which you have to respond or they automatically pay the supplier when the time runs out.
I've made several purchases via Aliexpress and found it to always work well. One supplier sent photos of the goods (20 laser printer cartridge chips) in their individual anti-static bags and the outer packet with the address label before they sent them. Arrived in 8 days and at a total cost of 4.00.
vidjoman is online now   Reply With Quote
Old 8th Jun 2018, 3:21 pm   #58
MrBungle
Nonode
 
MrBungle's Avatar
 
Join Date: Jun 2016
Location: London, UK.
Posts: 2,372
Default Re: HT / filament transformers from Aliexpress

They’re pretty good generally. I got a steal on some AD8307’s on aliexpress. Look to be genuine but 3 for 10 instead of 10 a go from RS. Certainly work fine and agree with my other power meter.

Think I placed about 60 orders so far and this transformer and a soldering iron stand were the only lemons. Probably better outcome than Maplin. And cheaper!
MrBungle is online now   Reply With Quote
Reply

Thread Tools



All times are GMT +1. The time now is 2:30 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Copyright ©2002 - 2018, Paul Stenning.