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Hi:
I am fixing a 7904 that has a busted power supply.
Both inverter transistors (Q1234 and Q1241) are busted
due to a connection to 240V while setup for 115V.
The transistors are Motorola 151-03-6800 and I will be
looking around for a replacement of the same kind, but
I was also wondering if anybody has has any success
trying more modern replacements for these parts.
Any suggestion about similar parts would be appreciated.
Regards
Tony
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?
Tucker has them for $5 each. Eight in stock. Tucker is a good,
reliable?vendor.
?
?
Best regards,
Tom
?
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Show quoted text
----- Original Message -----
Sent: Sunday, June 30, 2013 2:14 PM
Subject: [TekScopes] 7904
transistors
?
Hi:
I am fixing a 7904 that has a busted power supply.
Both
inverter transistors (Q1234 and Q1241) are busted
due to a connection to
240V while setup for 115V.
The transistors are Motorola 151-03-6800 and
I will be
looking around for a replacement of the same kind, but
I was
also wondering if anybody has has any success
trying more modern
replacements for these parts.
Any suggestion about similar parts would
be appreciated.
Regards
Tony
|
Transistor 151-0368-00 is a 2N6300.
This is a Tektronix part number.
Motorola may have been the only supplier.
This transistor appears to be available from:
for $1.62 each.
Hope this helps. This was located by my friend Google.
73
Glenn
WB4UIV
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Show quoted text
At 02:14 PM 6/30/2013, you wrote: Hi:
I am fixing a 7904 that has a busted power supply.
Both inverter transistors (Q1234 and Q1241) are busted
due to a connection to 240V while setup for 115V.
The transistors are Motorola 151-03-6800 and I will be
looking around for a replacement of the same kind, but
I was also wondering if anybody has has any success
trying more modern replacements for these parts.
Any suggestion about similar parts would be appreciated.
Regards
Tony
------------------------------------
Yahoo! Groups Links
|
Hi Glenn,
?
The 2N6300 shows up as a NPN Darlington in a TO-66 package.
?
So I am not sure VeroniaNorthern has the equivalent part number right. They
do carry original Tek parts though and most likely it will be the right
part.
?
The service manual for the early 7904 calls out an RCA 61577 as a
replacement. In any case, the schematic shows a NPN transistor in the circuit,
not a darlington.
?
Regards,
Tom
?
toggle quoted message
Show quoted text
----- Original Message -----
Sent: Sunday, June 30, 2013 2:54 PM
Subject: Re: [TekScopes] 7904
transistors
?
Transistor 151-0368-00 is a 2N6300.
This is a Tektronix part
number.
Motorola may have been the only supplier.
This transistor
appears to be available from:
for
$1.62 each.
Hope this helps. This was located by my friend
Google.
73
Glenn
WB4UIV
At 02:14 PM 6/30/2013, you
wrote:
>Hi:
>
>I am fixing a 7904 that has a busted power
supply.
>Both inverter transistors (Q1234 and Q1241) are
busted
>due to a connection to 240V while setup for
115V.
>
>The transistors are Motorola 151-03-6800 and I will
be
>looking around for a replacement of the same kind, but
>I was
also wondering if anybody has has any success
>trying more modern
replacements for these parts.
>
>Any suggestion about similar
parts would be
appreciated.
>
>Regards
>Tony
>
>
>
>------------------------------------
>
>Yahoo!
Groups Links
>
>
>
|
Tony
151-0368-00 are commonly used in the 'hi-efficiency' 7K series PSU.
This translates to the 2N6300, recently available from Ebay (china
source).
?In some mainframes, where higher power is required, (eg 7844) Tek
'selected' the 2N6300 and called it a 151-0386-01. Sphere lists the
-01 version as MJ13015. There are 3 available on Ebay now for $19+
(& same vendor has more from time to time).
In my experience the China parts are iffy, the MJ13015 works fine.
Chris HJ
On 30/06/2013 19:14, atonizzo wrote:
toggle quoted message
Show quoted text
?
Hi:
I am fixing a 7904 that has a busted power supply.
Both inverter transistors (Q1234 and Q1241) are busted
due to a connection to 240V while setup for 115V.
The transistors are Motorola 151-03-6800 and I will be
looking around for a replacement of the same kind, but
I was also wondering if anybody has has any success
trying more modern replacements for these parts.
Any suggestion about similar parts would be appreciated.
Regards
Tony
|
Hi Tony,
I used the BU208A from ST with good result.
G?ran
|
I have also used the BU 208 for repair. No problems after 1 year.
Mike
Sent from Yahoo! Mail on Android
|
From:
G?ran Krusell ;
To:
TekScopes@... ;
Subject:
[TekScopes] Re: 7904 transistors
Sent:
Sun, Jun 30, 2013 9:10:06 PM
?
Hi Tony,
I used the BU208A from ST with good result.
G?ran
|
|
G?ran: I used the BU208A from ST with good result. Thanks for the tip, and also thanks to all those that chimed in. One thing I noticed is that the part number is actually 151-0368-00 and not 151-03-6800 as I was thinking. This opened up a lot more search results. I am confused. If the 151-0368-00 is the 2N6300, this seems to be a puzzling choice, since the datasheet for the 2N6300 I am looking at shows the part as designed for "General purpose power amplifier and low frequency switching applications". Also, it shows an absolute maximum rating for the collector-emitter voltage of 60V, which seems hardly a good choice for the switching transistors of the power supply: The voltage at the switching node of the power supply toggles between 0 and rectified line voltage and this voltage appears between the collector and emitter of the two transistors (at different instants). A 60V maximum for collector-emitter will fry the 2n6300 transistors immediately. Maybe I am missing something... The BU208A seems to be a much more sensible choice, with its 700V Vceo(MAX) although being now obsoleted I will have to look for some inventory leftovers. The BUX48A is in production, and might be a good candidate as well, and it is specifically designed for switching regulators. Tony
|
Yellow book says 2N6308, if that helps... -ls- "atonizzo" <atonizzo@...> wrote:
G?ran:
I used the BU208A from ST with good result. Thanks for the tip, and also thanks to all those that
chimed in. One thing I noticed is that the part number
is actually 151-0368-00 and not 151-03-6800 as I was
thinking. This opened up a lot more search results.
I am confused. If the 151-0368-00 is the 2N6300, this seems
to be a puzzling choice, since the datasheet for the 2N6300
I am looking at shows the part as designed for "General
purpose power amplifier and low frequency switching
applications". Also, it shows an absolute maximum rating
for the collector-emitter voltage of 60V, which seems
hardly a good choice for the switching transistors of
the power supply: The voltage at the switching node of
the power supply toggles between 0 and rectified line voltage
and this voltage appears between the collector and emitter
of the two transistors (at different instants). A 60V
maximum for collector-emitter will fry the 2n6300 transistors
immediately.
Maybe I am missing something...
The BU208A seems to be a much more sensible choice, with its
700V Vceo(MAX) although being now obsoleted I will have to
look for some inventory leftovers. The BUX48A is in production,
and might be a good candidate as well, and it is specifically
designed for switching regulators.
Tony
------------------------------------
Yahoo! Groups Links
|
The book says 2N6308 in a TO-3 package. It also says the -01 parts were selected for Toff > 3uS but not the test conditions. As far as I can tell, the normal parts were rated to have a Toff of < 3uS. I would probably try using a 2N6545 as a replacement but only because I have a whole drawer full of them. It is a pretty standard offline power switch application. I think a BUX48 or 2N6547 would work well. On Sun, 30 Jun 2013 21:37:52 +0100, Christopher Hilton-Johnson <chj@...> wrote: Tony
151-0368-00 are commonly used in the 'hi-efficiency' 7K series PSU. This
translates to the 2N6300, recently available from Ebay (china source).
In some mainframes, where higher power is required, (eg 7844) Tek
'selected' the 2N6300 and called it a 151-0386-01. Sphere lists the -01
version as MJ13015. There are 3 available on Ebay now for $19+ (& same
vendor has more from time to time).
In my experience the China parts are iffy, the MJ13015 works fine.
Chris HJ
On 30/06/2013 19:14, atonizzo wrote:
Hi:
I am fixing a 7904 that has a busted power supply.
Both inverter transistors (Q1234 and Q1241) are busted
due to a connection to 240V while setup for 115V.
The transistors are Motorola 151-03-6800 and I will be
looking around for a replacement of the same kind, but
I was also wondering if anybody has has any success
trying more modern replacements for these parts.
Any suggestion about similar parts would be appreciated.
Regards
Tony
|
oops finger trouble: for 2N6300 read 2N6308 - apologies
On 30/06/2013 21:37, Christopher
Hilton-Johnson wrote:
toggle quoted message
Show quoted text
?
Tony
151-0368-00 are commonly used in the 'hi-efficiency' 7K
series PSU. This translates to the 2N6300, recently
available from Ebay (china source).
?In some mainframes, where higher power is required, (eg
7844) Tek 'selected' the 2N6300 and called it a
151-0386-01. Sphere lists the -01 version as MJ13015.
There are 3 available on Ebay now for $19+ (& same
vendor has more from time to time).
In my experience the China parts are iffy, the MJ13015
works fine.
Chris HJ
On 30/06/2013 19:14, atonizzo
wrote:
?
Hi:
I am fixing a 7904 that has a busted power supply.
Both inverter transistors (Q1234 and Q1241) are busted
due to a connection to 240V while setup for 115V.
The transistors are Motorola 151-03-6800 and I will be
looking around for a replacement of the same kind, but
I was also wondering if anybody has has any success
trying more modern replacements for these parts.
Any suggestion about similar parts would be
appreciated.
Regards
Tony
|
2N6308s are available from US Distributors, do a google search. I found at least three vendors, and the ubiquitous Chinese on Ebay.
toggle quoted message
Show quoted text
--- In TekScopes@..., Christopher Hilton-Johnson <chj@...> wrote:
oops finger trouble: for 2N6300 read 2N6308 - apologies
On 30/06/2013 21:37, Christopher Hilton-Johnson wrote:
Tony
151-0368-00 are commonly used in the 'hi-efficiency' 7K series PSU.
This translates to the 2N6300, recently available from Ebay (china
source).
In some mainframes, where higher power is required, (eg 7844) Tek
'selected' the 2N6300 and called it a 151-0386-01. Sphere lists the
-01 version as MJ13015. There are 3 available on Ebay now for $19+ (&
same vendor has more from time to time).
In my experience the China parts are iffy, the MJ13015 works fine.
Chris HJ
On 30/06/2013 19:14, atonizzo wrote:
Hi:
I am fixing a 7904 that has a busted power supply.
Both inverter transistors (Q1234 and Q1241) are busted
due to a connection to 240V while setup for 115V.
The transistors are Motorola 151-03-6800 and I will be
looking around for a replacement of the same kind, but
I was also wondering if anybody has has any success
trying more modern replacements for these parts.
Any suggestion about similar parts would be appreciated.
Regards
Tony
|
Yellow book says 2N6308, if that helps... The 2N6308 -with its 350 Vceo(MAX)- seems a much better choice than the 2N6300 (albeit marginal, for this applicaiton) but in any case, both 2N630X have a different package. The 151-0368-00 is a TO-3 (I have measured it with my caliper) while the 2N630X seem like a TO-66 package, which is incompatible. Unless someone explains me otherwise it seems like Goran's recommendation of using the BU208A is the only one that makes sense. The BUX48A also seems to be designed for this kind of high voltage switching applications. Tony
|
On Mon, Jul 1, 2013 at 10:02 AM, atonizzo <atonizzo@...> wrote:
Yellow book says 2N6308, if that helps... The 2N6308 -with its 350 Vceo(MAX)- seems a much better choice
than the 2N6300 (albeit marginal, for this applicaiton) but in
any case, both 2N630X have a different package. The 151-0368-00
is a TO-3 (I have measured it with my caliper) while the 2N630X
seem like a TO-66 package, which is incompatible.
Here's a datasheet showing 2N6308 is TO-3:
|
Hi,
I have hundreds of them here, literally. I am located in Germany -
but the NSA knows all about that. Ask them for details...
Cheers, Jochen DH6FAZ
Am 01.07.2013 13:56, schrieb
taylorvandy:
toggle quoted message
Show quoted text
?
2N6308s are available from US Distributors, do a google
search. I found at least three vendors, and the ubiquitous
Chinese on Ebay.
--- In TekScopes@...,
Christopher Hilton-Johnson wrote:
>
> oops finger trouble: for 2N6300 read 2N6308 -
apologies
>
> On 30/06/2013 21:37, Christopher Hilton-Johnson
wrote:
> >
> > Tony
> > 151-0368-00 are commonly used in the
'hi-efficiency' 7K series PSU.
> > This translates to the 2N6300, recently
available from Ebay (china
> > source).
> > In some mainframes, where higher power is
required, (eg 7844) Tek
> > 'selected' the 2N6300 and called it a
151-0386-01. Sphere lists the
> > -01 version as MJ13015. There are 3 available on
Ebay now for $19+ (&
> > same vendor has more from time to time).
> > In my experience the China parts are iffy, the
MJ13015 works fine.
> >
> > Chris HJ
> >
> > On 30/06/2013 19:14, atonizzo wrote:
> >>
> >> Hi:
> >>
> >> I am fixing a 7904 that has a busted power
supply.
> >> Both inverter transistors (Q1234 and Q1241)
are busted
> >> due to a connection to 240V while setup for
115V.
> >>
> >> The transistors are Motorola 151-03-6800 and
I will be
> >> looking around for a replacement of the same
kind, but
> >> I was also wondering if anybody has has any
success
> >> trying more modern replacements for these
parts.
> >>
> >> Any suggestion about similar parts would be
appreciated.
> >>
> >> Regards
> >> Tony
> >>
> >
> >
>
|
On Sun, Jun 30, 2013 at 02:10 PM, G?ran Krusell <goran.krusell@...> wrote:
Hi Tony,
I used the BU208A from ST with good result.
G?ran
On Sun, Jun 30, 2013 at 02:10 PM, G?ran Krusell <goran.krusell@...> wrote:
Hi Tony,
I used the BU208A from ST with good result.
G?ran
The BU208A is *>not<* a good idea. With a full set of modules the current load pushes past the SOA at the duty cycle used by the power supply. Its gets way too hot.. And once it gets hot it derates further. At 200V it exceeds the current pulled by a fully loaded 7904. This leads to thermal runaway which will then lead to a 200F back heat sink and eventual transistor failure. It will work tho, for short periods.. I am looking into upgrading this transistor to a more powerful one. I have ordered up some BUX48A's. I dont know if these work yet tho.. I will report back here once I have a well tested better then orginal sub.. MAYBE.. Untested so far.. I get them this week
|
On Sun, Jun 30, 2013 at 02:10 PM, G?ran Krusell <goran.krusell@...> wrote:
Hi Tony,
I used the BU208A from ST with good result.
G?ran
The BU208A is *>not<* a good idea. With a full set of modules the current load pushes past the SOA at the duty cycle used by the power supply. Its gets way too hot.. And once it gets hot it derates further. At 200V it exceeds the current pulled by a fully loaded 7904. This leads to thermal runaway which will then lead to a 200F back heat sink and eventual transistor failure. It will work tho, for short periods.. I am looking into upgrading this transistor to a more powerful one. I have ordered up some BUX48A's. I dont know if these work yet tho.. I will report back here once I have a well tested better then orginal sub.. MAYBE.. Untested so far.. I get them this week
|
David Hess