GK-71 - economical build.

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jack
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#451 Re: GK-71 - economical build.

Post by jack »

Paul Barker wrote: Sun Aug 20, 2017 8:55 am Or just host stuff within a Google doc and instead of an embedded image post the link to a Google doc (accessible to anyone who has the link). That's probably the way forward until a competitor to photobucket springs up.
For NEONIXIE-L (which I own & manage) I have set up a Google Drive with permissions set to "Anyone on the internet can find or view" - you should be able to browse r/o the link. Google Drive gives you 15Gb for free, however do read the T&Cs.

One nice thing about Google Drive is if you have a Google Group, e.g. neonixie-l, you can give that whole group certain privileges, e.g. write access to an upload directory, but r/o to the rest of the tree - the advantage here is that for write access, you don't have to invite the group members individually - access rights are automatically granted as you specify to any member of the group, i.e. Google Drive is an excellent backing store for any Google Group... they actually thought about this!
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Paul Barker
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#452 Re: GK-71 - economical build.

Post by Paul Barker »

Oh and once the photos i want are downloaded I'll leave photobucket. The only possibility of backtracking is if their action results in sufficient loss of hits to their prodigeous slow opening advertisers flags whihc make their product barely useable asit is.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
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#453 Re: GK-71 - economical build.

Post by Ant »

Have a look at Flickr Paul, ive started to use it for the same reason. The only problem ive found with it is that i cant figure out how to get the bbcode link on an android phone.
Just means that if I want to post a picture I have to use the mac.
The only difference in terms of posting a pic is that it adds a link to the image underneath the posted pic in blue to generate traffic onto the Flickr site which is fair enough.
No adverts either and its pretty user friendly
Also starring Rex Hamilton as Abraham Lincoln

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#454 Re: GK-71 - economical build.

Post by Paul Barker »

Thanks mate.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
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#455 Re: GK-71 - economical build.

Post by ratbagp »

I just used this today to post pictures at the audio group meeting near Washington DC yesterday.

https://vgy.me/

It's a free service and was quite easy to use and you don't even have to sign up. And yes, all my Photobucket photos are now useless. Somehow I doubt that company is going to be around all that long. Nobody will trust them any more, even if they go back to a free model.

You can see the results at

http://www.dcaudiodiy.com/phpBB3/viewto ... 1&start=60

The amp came from David Berning and is a push-pull 6B4G OTL. You can read more about his company here.

http://davidberning.com/

Although he is a commercial manufacturer, he is very much interested in the DIY movement. And for Ray P, he is a keen cyclist.

ray
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#456 Re: GK-71 - economical build.

Post by pre65 »

Inspired by Steve's success with choke placement I'm going to do some mods to the GK-71 monoblocks.

1) Put both chokes in the negative rail.

2) Fit a 10K 100W bleeder resistor. (can't remember why I did not do that when the amps were created. :oops: )

3) Increase the first capacitor bank value to 500uf.(2 X 1000uf)

4) Change the 0v point location.(Fig 3 diagram)

5) Bypass one choke with 100R and 0.25uf as per diagram.(Fig 3)

I'd really like to do these mods one at a time to hear what difference (if any) each step makes but I won't, for various reasons.
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#457 Re: GK-71 - economical build.

Post by pre65 »

Apart from the resistor/cap across L1 one amp is done.

Just waiting to find out what those do. :)
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#458 Re: GK-71 - economical build.

Post by Nick »

They are a snubber network as Steve has said in the other thread.
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#459 Re: GK-71 - economical build.

Post by pre65 »

Nick wrote: Mon Jan 01, 2018 2:41 pm They are a snubber network as Steve has said in the other thread.
Thanks Nick.

I'll leave it off for now for the same reason Steve did.
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#460 Re: GK-71 - economical build.

Post by pre65 »

Got everything ready for switch on late this morning.

I noticed that one 6D22s was not lit up, and upon investigation one of the base tags was broken off underneath, and not repairable. :(

Fortunately I found a new base in the spares box, so I'm in the process of fitting it. It's a bit fiddly to get to, especially with clumsy fingers, but I'll try and be patient.
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#461 Re: GK-71 - economical build.

Post by pre65 »

By gumm, it was fiddly to get to the nuts holding the 6D22s damper diode bracket.More so when re-assembling,

Anyway, we have a fully working pair of amps now. :D

First thing to note is the alloy plate to which the bleeder resistor fits is bleeding HOT.

Second thing is, the heatsink for the GK-71 filament board (Andrew Ls type) seems less hot. :?

Re what I'm hearing, the various bits that make up the whole seem more distinct, but not detrimental to the sum of those bits. More listening is in order.

But bear in mind I have done several mods in one go.
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#462 Re: GK-71 - economical build.

Post by Mike H »

pre65 wrote: Mon Jan 01, 2018 10:28 am Inspired by Steve's success with choke placement I'm going to do some mods to the GK-71 monoblocks.

1) Put both chokes in the negative rail.
Why?
 
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#463 Re: GK-71 - economical build.

Post by pre65 »

Mike H wrote: Thu Jan 04, 2018 10:57 am
pre65 wrote: Mon Jan 01, 2018 10:28 am Inspired by Steve's success with choke placement I'm going to do some mods to the GK-71 monoblocks.

1) Put both chokes in the negative rail.
Why?
A) Because I can.

B) Why not ?

C) I felt like it.

D) I wanted something to do.

E) It might make a difference.

F) There is no F (copyright I Ivimey)

G) Steve C did it.
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#464 Re: GK-71 - economical build.

Post by pre65 »

Re the bleeder resistor, I'm going to put another 10K in series with the existing one to half the current.

Won't be till next week now.
The only thing necessary for the triumph of evil is for good men to do nothing.

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#465 Re: GK-71 - economical build.

Post by Mike H »

I have successfully used a resistor like that and indeed it was 10k, just so happens. Need to make sure power handling is good enough.

pre65 wrote: Thu Jan 04, 2018 11:05 am
A) Because I can.

B) Why not ?

C) I felt like it.

D) I wanted something to do.

E) It might make a difference.

F) There is no F (copyright I Ivimey)

G) Steve C did it.
OK sorry that sounded a bit curt - by all means try it, personally I think there shouldn't be any difference to how it basically works, but YMMV.
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
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