[TenTec] Spare MPSW01 or TN2219A

[Vicens Llario]

Dear Gerald

Many thanks for coming back to my message. The original bias transistor used
in the transverter is a MPSW01 capable of 1W power disipation at a high
colector current of 1A. There is not too much room on the PCB to play with
the legs and that is why I am looking for a pin to pin exact replacement.
The original transistor has the EBC pins left to right as you mention. While
looking at the TN2219 datasheet I thought that it was a possible candidate.
I contacted Jameco and the price for 9 pieces is just around $1 but the USPS
shiping they propose is $22. Paul Clinton of Ten Tec Service has come back
with a fair proposal, $1 per transistor plus $6 shiping and handling. I will
decide what to do during the weekend but have not too many options.

Best 72

Vicenç, EA3ADV


2007/9/15, Dr. Gerald N. Johnson <geraldj at storm.weather.net>:
>
> On Wed, 2007-09-12 at 20:55 +0200, Vicenç Llario wrote:
> > To the Ten Tec list members
> >
> > Last weekend I was troubleshooting the TX side of my 1208 transverter
> > and found that the bias transistor Q14 was faulty. I tried to find a
> > replacement in the 2 main electronic components shops in my area but I
> > did not manage to find it. It seems that the original MPSW01 NPN
> > transistor is not so common and also it is out of production. I wonder
> > if perhaps some member of the list may have one of those transistors and
> > would be willing to part with it. I would obviously pay the component as
> > well as the shipping costs to Barcelona, Spain. While looking for an
> > alternative I found that the Fairchild TN2219A has exactly the same
> > features as the original used in the transverter. If nobody has a
> > replacement transistor in the junk box I would appreciate advice on
> where
> > to get one.
> >
> > Many thanks in advance for your kind help and best 72
> >
> > Vicenç, EA3ADV
>
> If a TN2219A works, the transistor isn't critical. Its a 200 ma NPN with
> maybe half a watt dissipation. While the device may do (at least the
> metal cased 2N2219) half a watt of RF up to 50 MHz, this doesn't sound
> like a RF transistor but just a switching transistor. Same chip as a
> 2N2222, but a bigger case (at least for the equivalent 2N2219).
>
> The main feature of the MPSW01 was probably cost.
>
> The NTE cross, NTE-128P, is a fat TO-92 package with a metal heatsink
> fin out the top, with pins E B C left to right. Different from some
> makers that put the collector in the middle in the plastic in line
> package. The 128P is a bit sturdier than a 2N2219, but not much. 2N3904,
> or 2N4104, fairly common audio transistors ought to work too.
> --
> 73, Jerry, K0CQ,
> All content copyright Dr. Gerald N. Johnson, electrical engineer
>
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