The front end seems to have gone out on this set. FM seems fine, AM
works on the stronger stations, and there's nothing but a low level
noise on SW.

I'm suspecting the usual Q1 problem


What would be a good replacement? Is there a quick cure to prevent
future zappings?




mike


--

__ __ __ __ __ __ __ __
/ /\ / /\ / /\ / /\ / /\ / /\ / /\ / /
/ /\ \/ /\ \/ /\ \/ /
/_/ \/_/ \/_/ \/_/ \/_/ \/_/ \/_/ \/_/

..let the cat out to reply..

Many people have used an MPF102 as a
replacement. I tried it on mine and found that
it worked, but had about half the sensitivity of
the original.

The original is a 2SK152 Data can be found he
http://nte01.nteinc.com/nte/NTExRefSemiProd.nsf/$$Search?OpenForm

The replacement is a NTE312.

I scored a VHF FET from an old 46/49MHz cordless
phone, and used that. There was one drawback to my
substitution, The pinchoff voltage is different, and the RF
gain control has no effect. Therefore, the gain is set
wide open, since you cant bias the FET off. I cant
remember the FET number.

The good point is that sensitivity is hotter than with the
original.

Add a pair of 1n4148/914 diodes back to back across the
antenna jack to eliminate this problem in the future.

YMMV - Good luck

N3KCT wrote:

Many people have used an MPF102 as a
replacement. I tried it on mine and found that
it worked, but had about half the sensitivity of
the original.

The original is a 2SK152 Data can be found he
http://nte01.nteinc.com/nte/NTExRefSemiProd.nsf/$$Search?OpenForm

The replacement is a NTE312.

I scored a VHF FET from an old 46/49MHz cordless
phone, and used that. There was one drawback to my
substitution, The pinchoff voltage is different, and the RF
gain control has no effect. Therefore, the gain is set
wide open, since you cant bias the FET off. I cant
remember the FET number.

The good point is that sensitivity is hotter than with the
original.

Add a pair of 1n4148/914 diodes back to back across the
antenna jack to eliminate this problem in the future.

YMMV - Good luck

Do you think the NTE-312 would perform the same as the 2SK152?


-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

Do you think the NTE-312 would perform the same as the 2SK152?

The NTE-312 is the cross for 2SK152. They should be
electrically identical, and should perform as such.

"N3KCT" wrote in message
news
Do you think the NTE-312 would perform the same as the 2SK152?

The NTE-312 is the cross for 2SK152. They should be
electrically identical, and should perform as such.

Well, not exactly. It's the closest match NTE has to the 2SK152, and
"should" function in most circuits. That isn't to say it is an exact
replacement. The NTE device may have a higher noise figure, for example,
which could be obvious on the higher bands. This company in Ireland claims
to be selling the 2SK152 for 62 US cents apiece:
http://www.donberg.ie/descript/2/2sk152.htm

The J310 FET is pretty good, and available from Kits & Parts, and either
Mouser or DigiKey; I can't remember who I got mine from. The price is right
and it might be worth buying several and swapping them in for best
performance.

"PM"

Paul_Morphy wrote:

"N3KCT" wrote in message
news
Do you think the NTE-312 would perform the same as the 2SK152?

The NTE-312 is the cross for 2SK152. They should be
electrically identical, and should perform as such.

Well, not exactly. It's the closest match NTE has to the 2SK152, and
"should" function in most circuits. That isn't to say it is an exact
replacement. The NTE device may have a higher noise figure, for example,
which could be obvious on the higher bands. This company in Ireland claims
to be selling the 2SK152 for 62 US cents apiece:
http://www.donberg.ie/descript/2/2sk152.htm

The J310 FET is pretty good, and available from Kits & Parts, and either
Mouser or DigiKey; I can't remember who I got mine from. The price is right
and it might be worth buying several and swapping them in for best
performance.

"PM"

Why is the 2SK152 so rare?


-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

In article , starman wrote:
Paul_Morphy wrote:

"N3KCT" wrote in message
news
Do you think the NTE-312 would perform the same as the 2SK152?

The NTE-312 is the cross for 2SK152. They should be
electrically identical, and should perform as such.

Well, not exactly. It's the closest match NTE has to the 2SK152, and
"should" function in most circuits. That isn't to say it is an exact
replacement. The NTE device may have a higher noise figure, for example,
which could be obvious on the higher bands. This company in Ireland claims
to be selling the 2SK152 for 62 US cents apiece:
http://www.donberg.ie/descript/2/2sk152.htm

NTE doesn't make anything, they just buy parts that are normally
not available in the US or at end of life, and then mark them up
by a factor of eight or so and sell them to the repair market.
They are a way for an independent electronics dealer (not that
there are many of those still around) to stock semiconductors
from the distribtution channel.

The J310 FET is pretty good, and available from Kits & Parts, and either
Mouser or DigiKey; I can't remember who I got mine from. The price is right
and it might be worth buying several and swapping them in for best
performance.

"PM"

Why is the 2SK152 so rare?

It is/was a proprietary Sony part. The datasheet says it was
designed for read amplifers in VCRs, so maybe there's some out
there that can obtained from scrap Betamax's.

(I've got the datasheet on my FTP directory at
ftp://ftp.eskimo.com/u/m/mzenier/Sony2sk152.pdf).

Mark Zenier Washington State resident