I have a suspect transistor in the MPX circuit of an HK330A receiver
that is not decoding stereo. The one in question, 2SA49, crosses on
the NTE site to an NTE126. I provide the specs for the 2SA49 and the
NTE126. Is this a good substitution? Might there be a less espensive
option (NTE126 is $4.86 or so).

2SA49 (PNP Ge)
Vcbo=-18V
Vebo=-12V
Vceo(sat)=?
Ic=-5mA
Pc=60mW
fT=?
hfe=30-200

(From the Japanese Transistor Manual
http://www.datasheetarchive.com/search.php?q=2SA49)

NTE126 (PNP Ge)
Vcbo=15V
Vebo=2.5V
Vceo=15V
Ic=100uA
Pc=150mW
fT=300Mhz
hfe=40

http://www.nteinc.com/specs/100to199/pdf/nte126.pdf

From what I have learned so far, the important parameters for this
application are Ic, fT, Vceo. Do I have enough information to select a
sub? Also, what is the significance of the negative values indicated on
the 2SA49 spec sheet, does this impact how I would install the
replacement?

wrote in message
oups.com...
I have a suspect transistor in the MPX circuit of an HK330A receiver
that is not decoding stereo. The one in question, 2SA49, crosses on
the NTE site to an NTE126. I provide the specs for the 2SA49 and the
NTE126. Is this a good substitution? Might there be a less espensive
option (NTE126 is $4.86 or so).

2SA49 (PNP Ge)
Vcbo=-18V
Vebo=-12V
Vceo(sat)=?
Ic=-5mA
Pc=60mW
fT=?
hfe=30-200

(From the Japanese Transistor Manual
http://www.datasheetarchive.com/search.php?q=2SA49)

NTE126 (PNP Ge)
Vcbo=15V
Vebo=2.5V
Vceo=15V
Ic=100uA
Pc=150mW
fT=300Mhz
hfe=40

http://www.nteinc.com/specs/100to199/pdf/nte126.pdf

From what I have learned so far, the important parameters for this
application are Ic, fT, Vceo. Do I have enough information to select a
sub? Also, what is the significance of the negative values indicated on
the 2SA49 spec sheet, does this impact how I would install the
replacement?


The Ic looks low on the replacement you have. It will depend on how the
device is used as to how important the paremeters are. In non critical
circuits the Vc, Ic, and having more hfe are important. Ft is important if
the device is used in high frequency (RF ) applications.

The negative values are usually put in for PNP devices in the spec sheets to
denote the collector is usually connected to the negative of the supply
voltage. It can be leftout by whoever prints the spec sheets. Just as if
you ask the price of something in the dollars price range and a guy says 25.
You usually think of dollars in the US and not 25 pennys or 25 dimes or 25
quarters. but he may say 25 dollars.

The 1996 Transistor Substitution manual lists 2SA1015 as a substitute for
the 2SA49.

wrote in message
oups.com...
I have a suspect transistor in the MPX circuit of an HK330A receiver
that is not decoding stereo. The one in question, 2SA49, crosses on
the NTE site to an NTE126. I provide the specs for the 2SA49 and the
NTE126. Is this a good substitution? Might there be a less espensive
option (NTE126 is $4.86 or so).

2SA49 (PNP Ge)
Vcbo=-18V
Vebo=-12V
Vceo(sat)=?
Ic=-5mA
Pc=60mW
fT=?
hfe=30-200

(From the Japanese Transistor Manual
http://www.datasheetarchive.com/search.php?q=2SA49)

NTE126 (PNP Ge)
Vcbo=15V
Vebo=2.5V
Vceo=15V
Ic=100uA
Pc=150mW
fT=300Mhz
hfe=40

http://www.nteinc.com/specs/100to199/pdf/nte126.pdf

From what I have learned so far, the important parameters for this
application are Ic, fT, Vceo. Do I have enough information to select a
sub? Also, what is the significance of the negative values indicated on
the 2SA49 spec sheet, does this impact how I would install the
replacement?

On 24 May 2006 06:24:10 -0700, put finger to
keyboard and composed:

I have a suspect transistor in the MPX circuit of an HK330A receiver
that is not decoding stereo. The one in question, 2SA49, crosses on
the NTE site to an NTE126. I provide the specs for the 2SA49 and the
NTE126. Is this a good substitution? Might there be a less espensive
option (NTE126 is $4.86 or so).

2SA49 (PNP Ge)
Vcbo=-18V
Vebo=-12V
Vceo(sat)=?
Ic=-5mA
Pc=60mW
fT=?
hfe=30-200

(From the Japanese Transistor Manual
http://www.datasheetarchive.com/search.php?q=2SA49)

NTE126 (PNP Ge)
Vcbo=15V
Vebo=2.5V
Vceo=15V
Ic=100uA

That's the collector-emitter cutoff current (Vce = 15V).

Pc=150mW
fT=300Mhz
hfe=40

This is the minimum hfe at collector currents of 10 - 100 milliamps
(Vce = 0.3 - 1.0 volts).

http://www.nteinc.com/specs/100to199/pdf/nte126.pdf

From what I have learned so far, the important parameters for this
application are Ic, fT, Vceo. Do I have enough information to select a
sub? Also, what is the significance of the negative values indicated on
the 2SA49 spec sheet, does this impact how I would install the
replacement?

My vrt databook lists AF124 ... 127, AF200 as possible replacements.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

AF124 (NTE160) looks to be a much better match.

I found a Sams cross reference manual at the library, and it too was
showing NTE126 as a sub for 2SA49, but NTE160 certainly looks better.
By the way, the Ic of 100uA for the NTE126 is incorrect, this
information is not on the datasheet, that is the value of the C-E
cutoff current, the Ic is not given in the datasheet, can it be
calculated? This stuff is all new to me, one would think NTE database
would cross to the on-the-face-of-it better choice of NTE160.

Backspace past "pdf" to get at the folders - change the "200to299 in similar
format to navigate.......

http://www.nteinc.com/specs/200to299/

Use DAP to queue downloads as many at once as you like.

http://www.download3k.com/Download-A...-dap8.exe.html




wrote in message
oups.com...
I have a suspect transistor in the MPX circuit of an HK330A receiver
that is not decoding stereo. The one in question, 2SA49, crosses on
the NTE site to an NTE126. I provide the specs for the 2SA49 and the
NTE126. Is this a good substitution? Might there be a less espensive
option (NTE126 is $4.86 or so).

2SA49 (PNP Ge)
Vcbo=-18V
Vebo=-12V
Vceo(sat)=?
Ic=-5mA
Pc=60mW
fT=?
hfe=30-200

(From the Japanese Transistor Manual
http://www.datasheetarchive.com/search.php?q=2SA49)

NTE126 (PNP Ge)
Vcbo=15V
Vebo=2.5V
Vceo=15V
Ic=100uA
Pc=150mW
fT=300Mhz
hfe=40

http://www.nteinc.com/specs/100to199/pdf/nte126.pdf

From what I have learned so far, the important parameters for this
application are Ic, fT, Vceo. Do I have enough information to select a
sub? Also, what is the significance of the negative values indicated on
the 2SA49 spec sheet, does this impact how I would install the
replacement?

"CLARENCE CLAY" wrote in message
news:Yj8dg.8302$qn2.129@trnddc04...
The 1996 Transistor Substitution manual lists 2SA1015 as a substitute for
the 2SA49.


It might work - but the 1015 looks like a Si type, if the original is part
of a matched pair or duplicated in another channel it might cause an
imbalance!