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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc. |
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1st Mar 2007, 4:28 pm | #1 |
Hexode
Join Date: Nov 2005
Location: Kent, UK.
Posts: 332
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5MK9 rectifier valve. Spares or equivalents??
Hi,
I have 4 similar tape machines from the 50s that were made in Japan and all use a 5MK9 valve rectifier. I am beginning to wonder how rare this valve might be and would like to stock up on a few spares. They have not gone wrong for all these years but who knows!!!! I would like to know if there are any equivalents one can use for this valve or where i can find replacements in the uk please? The other valves they use are quite common so no worries about that. if it helps anyone i can always post the circuit diagram of this machine. You can have a look at what they look like on this thread below: https://www.vintage-radio.net/forum/...ad.php?t=14892 many thanks indeed |
1st Mar 2007, 6:24 pm | #2 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,195
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Re: 5MK9 rectifier valve. Spares or equivalents??
Hi Jascha, any chance of a picture or the valve and some circuit details.
It may be that a common type such as an EZ80/81 or 5Z4 will do. If we know the base type and ratings it should be easier to advise. Ed |
1st Mar 2007, 8:35 pm | #3 |
Hexode
Join Date: Nov 2005
Location: Kent, UK.
Posts: 332
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Re: 5MK9 rectifier valve. Spares or equivalents??
Hi Ed,
The valve i am talking about is a 7 pin valve that is slightly longer in size than an ECC83. I shall attach a circuit diagram of my tape machine so you can see what this valve does. I also attach a few other pictures related to this valve. I have found a supplier who had 4 in all and i am buying them but it is worth knowing more about it. So i look forward to your replies. many thanks again |
1st Mar 2007, 8:48 pm | #4 |
Dekatron
Join Date: Sep 2005
Location: Seaford, East Sussex, UK.
Posts: 5,997
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Re: 5MK9 rectifier valve. Spares or equivalents??
http://www.mif.pg.gda.pl/homepages/f...33/5/5M-K9.pdf half wave rectifier 5V heater - I think you maybe wise to stock up.
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1st Mar 2007, 8:51 pm | #5 |
Retired Dormant Member
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
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Re: 5MK9 rectifier valve. Spares or equivalents??
You could probably get an EY91 to work with a bit of fiddling. Would need a resistor to correct the heater current.
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1st Mar 2007, 9:03 pm | #6 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,195
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Re: 5MK9 rectifier valve. Spares or equivalents??
Hi Jascha, it is a bit of an oddball. There are plenty of rectifiers of this size around but very few that don't have 6.3 or higher voltage heaters. As Jeffery says, you may do it with an EY91 (not that common either), or you may need to look at adding turns to the rectifier heater winding and getting a 6.3 volt valve (plenty of these about).
Ed |
1st Mar 2007, 9:13 pm | #7 |
Hexode
Join Date: Nov 2005
Location: Kent, UK.
Posts: 332
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Re: 5MK9 rectifier valve. Spares or equivalents??
Hi everyone,
Thanks for your replies....it sounds wise to stock up i think!!!! I will be in japan in April and i will definitely have alook around there to see if i find any lurking around too. I was told these are rare and were used for some japanese tape machines. If i can stick to the original i think it would be the safest bet. Thanks once again |
1st Mar 2007, 9:38 pm | #8 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,970
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Re: 5MK9 rectifier valve. Spares or equivalents??
If you rectify and smooth the 5V AC supply you'll get more than enough volts to use something like a 6X4/EZ90, but obviously this isn't an ideal solution. Or you could just use a silicon diode
Paul |
2nd Mar 2007, 10:21 pm | #9 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,195
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Re: 5MK9 rectifier valve. Spares or equivalents??
Hi Jascha, If you are in Tokyo the Ahiharbra(?) market under the station is like certain areas of London in the 50's for radio spares, you should be lucky there.
Ed |
2nd Mar 2007, 11:19 pm | #10 |
Hexode
Join Date: Nov 2005
Location: Kent, UK.
Posts: 332
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Re: 5MK9 rectifier valve. Spares or equivalents??
I go there every time i am in Tokyo (for work!!!). I love those tiny shops full of components....and the quality of the components is just very high quality too. It's called Akihabara.
MANY THANKS |