On Tuesday, November 25, 2014 6:28:40 PM UTC-5, Ross Archer wrote:
On Monday, November 24, 2014 1:23:12 PM UTC-8, marc wrote:
Michael Black wrote:

If you do a search, the need to replace that front end jfet (I'm assuning
that's where the part is) is fairly common, so there are various people on
the web writing about replacing it. I think they've often used an
available jfet, which won't be optimum, but will work better than a
bipolar transistor.

I've nbever had 5 leds on 153 DLF, now I have ...

Of course, I do not know anybody close to my location with such a radio (Furnes/Ypres/Dunkeirk/Lille)...

Same for AM radios. It coul be that shortwave is a little bit lees, but it is OK ...

Ali has them: 2sk152:

http://www.aliexpress.com/item/IC-2S...951278662.html



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It ain't cheap, but an exact replacement appears to be available through:
http://www.bdent.com/2sk152-2-sony-transistor.html

Ali Baba IS CHEAPEST-a bag of 10 FOR $18.

On Tuesday, November 25, 2014 10:25:03 PM UTC-8, wrote:
On Tuesday, November 25, 2014 6:28:40 PM UTC-5, Ross Archer wrote:
On Monday, November 24, 2014 1:23:12 PM UTC-8, marc wrote:
Michael Black wrote:

If you do a search, the need to replace that front end jfet (I'm assuning
that's where the part is) is fairly common, so there are various people on
the web writing about replacing it. I think they've often used an
available jfet, which won't be optimum, but will work better than a
bipolar transistor.

I've nbever had 5 leds on 153 DLF, now I have ...

Of course, I do not know anybody close to my location with such a radio (Furnes/Ypres/Dunkeirk/Lille)...

Same for AM radios. It coul be that shortwave is a little bit lees, but it is OK ...

Ali has them: 2sk152:

http://www.aliexpress.com/item/IC-2S...951278662.html



--
--
What's on Shortwave guide: choose an hour, go!
http://shortwave.tk
700+ Radio Stations on SW http://swstations.tk
300+ languages on SW http://radiolanguages.tk

It ain't cheap, but an exact replacement appears to be available through:
http://www.bdent.com/2sk152-2-sony-transistor.html

Ali Baba IS CHEAPEST-a bag of 10 FOR $18.

However, they do not specify which gain batch these come from. The 2010 uses a 2SK152-2.
That's the exact replacement, for gain and performance.

2sk170?

On 11/24/2014 12:20 PM, Michael Black wrote:
On Sun, 23 Nov 2014, marc wrote:


Hello,

I fit a 3 pin plug and tried some transistors ..

I get a good result with a C369 ...

Any comments?

I did not find my stock replacements, but have a box of spare parts
from ?? all kind of old electronics ... ;-)


If the replacement isn't a jfet, it won't work at all. That "C369"
sounds more like a bipolar transistor, and if you get "good results",
it's only because the transitor is letting the signal pass through. It
can't amplify, bipolar transistors need forward biasing, and that's not
there since the transistor is supposed to be a jfet.

If you do a search, the need to replace that front end jfet (I'm
assuning that's where the part is) is fairly common, so there are
various people on the web writing about replacing it. I think they've
often used an available jfet, which won't be optimum, but will work
better than a bipolar transistor.

Michael

Google 2SK152 and you will find many sources for original Sony JFETS


Hello,

I fit a 3 pin plug and tried some transistors ..

I get a good result with a C369 ...

Any comments?

I did not find my stock replacements, but have a box of spare parts from ?? all kind of old electronics ... ;-)


Marc

Since no one else has mentioned it, ISTR that people have used 2N3819 and MPF102 to replace the front end JFET. When I Googled MPF102, one link came up for 10 for $4.80 on eBay. It seems to me that any small-signal n-channel jfet will work well enough to get you a functioning radio (but I have never actually made this repair). While you are at it, you might also want to put parallel back-to-back Si switching diodes (1N914 or 1N4148) between the gate and ground to protect the jfet from ESD.

On Thu, 27 Nov 2014, wrote:

Since no one else has mentioned it, ISTR that people have used 2N3819
and MPF102 to replace the front end JFET. When I Googled MPF102, one
link came up for 10 for $4.80 on eBay. It seems to me that any
small-signal n-channel jfet will work well enough to get you a
functioning radio (but I have never actually made this repair). While
you are at it, you might also want to put parallel back-to-back Si
switching diodes (1N914 or 1N4148) between the gate and ground to
protect the jfet from ESD.


I certainly alluded to that when I suggested doing a search for what
people did when they blew out the original FET.

In both cases, the devices you mention are very available jfets. They may
or may not be the best choice (especially if the biasing isnt' changed)
but they are the most likely devices to be available through hobby
channels. And people seem satisfied with the results. Michael Covington
had a hint up about this, and he's one of those people who'd be fussy if
he felt it mattered what the exact device was.

Michael

On 11/23/2014 02:23 PM, marc wrote:
Any comparable polarity low noise fet you can squeeze in should be a
vast improvement.
Hello,

I fit a 3 pin plug and tried some transistors ..

I get a good result with a C369 ...

Any comments?

I did not find my stock replacements, but have a box of spare parts from ?? all kind of old electronics ... ;-)


Marc