I've found all the parts for this project except for the ZTX330 and 2N5950
transistors which seem to be extinct. The 2N5950 is available at some
commercial venues but I only need one of em. Are there readily available
subs for these? I'm getting a little discouraged. Thanks.
Andy W1AWB

Andy Bullington wrote:
I've found all the parts for this project except for the ZTX330 and 2N5950
transistors which seem to be extinct. The 2N5950 is available at some
commercial venues but I only need one of em. Are there readily available
subs for these? I'm getting a little discouraged. Thanks.
=========================================
ZTX 330 equivalents BC349C and 2N3904

2N5950 is not listed in my reference docs : Tower's International
transistor selector (1984 edition)
However via Google I found an e-Bay site with the following info :
2N5950 N-CHANNEL JFET AMPLIFIER

Have a look at the spec(via Google) of the 2N5950 and I am sure you'll
find an equivalent . Parts Express sell the 2N5950 for $0.35 each.

Frank GM0CSZ / KN6WH

Thanks guys...didn't think to look at Parts Express.
"Highland Ham" wrote in message
...
Andy Bullington wrote:
I've found all the parts for this project except for the ZTX330 and
2N5950 transistors which seem to be extinct. The 2N5950 is available at
some commercial venues but I only need one of em. Are there readily
available subs for these? I'm getting a little discouraged. Thanks.
=========================================
ZTX 330 equivalents BC349C and 2N3904

2N5950 is not listed in my reference docs : Tower's International
transistor selector (1984 edition)
However via Google I found an e-Bay site with the following info :
2N5950 N-CHANNEL JFET AMPLIFIER

Have a look at the spec(via Google) of the 2N5950 and I am sure you'll
find an equivalent . Parts Express sell the 2N5950 for $0.35 each.

Frank GM0CSZ / KN6WH

On Tue, 07 Mar 2006 13:27:05 GMT,
wrote:

On Tue, 7 Mar 2006 07:44:16 -0500, "Andy Bullington"
wrote:

I've found all the parts for this project except for the ZTX330 and 2N5950
transistors which seem to be extinct. The 2N5950 is available at some
commercial venues but I only need one of em. Are there readily available
subs for these? I'm getting a little discouraged. Thanks.
Andy W1AWB


I'd think the 40673 mosfets harder to find though easy to substitute.

The ZTX330 is generic and a 2n3904, 2n2222 or similar should
work fine. For the 2n5950 I'd use a MPF102, 2n3819 or J310 fet as
those are easy to get. The transistors used are in non critical
circuits so substitutions should easily work.

Generally speaking the transistors and IC used reflects those
available to the author and reasonable substitutions will work
with no degradation.

The only parts that require care are the MAV-11 MIMICs and the SBL-3
as they helps define many of the modified recievers desired
characteristics.

Allison

These folks have a decent supply of 40673s. They advertise being
"Leaders on the trailing edge of technology". I don't know what their
onesy - twosey policy is, having never done business with them.
http://www.rocelec.com/

Also, search for "NTE" equivalents.

Russ

Hi Andy,

I don't know if you want to do any experimenting. If you do, one
thing to consideris to not use a 602 as the product detector in that
conversion. I have done it last month and it worked ok but I didn't
really see any difference in the performance of the receiver.
the original product detector, being made from diodes, was a low
impedance device. Consider replacing it with a DBM, since you already
have a low impedance source of 50 KHz LO. If you make the conversion
the authors did you end up moving the components to use the oscillator
in the 602 and end up having to attenuate the IF signal coming into
the 602 also. My only concern is the frequency response of the
packaged DBMs - they are speced at 500 KHz as the lower frequency
limit. Maybe using them at 50 KHz is pushing them too far.
I DID make the power supply and audio amp mods. The audio amp,
especially, is extremely crude. I can't believe Drake actually built
their audio amp that way (Class A with a transformer). I used a
simple little 380 IC mounted right next to the volume control and it
works fantastic.
I haven't done the earlier mixer mods yet, but so far the improvements
in heat reduction and consequent VFO stability are worthwhile.

Rick K2XT

Boy have I learned a lot on this little search...thanks to you guys. NTE
lists the NTE 222 as equivalent to the 40673 and Parts Express has them for
just under 9 bucks each. RF Parts has the 40673 for about $7.
"Russ" wrote in message
...
On Tue, 07 Mar 2006 13:27:05 GMT,
wrote:

On Tue, 7 Mar 2006 07:44:16 -0500, "Andy Bullington"
wrote:

I've found all the parts for this project except for the ZTX330 and
2N5950
transistors which seem to be extinct. The 2N5950 is available at some
commercial venues but I only need one of em. Are there readily available
subs for these? I'm getting a little discouraged. Thanks.
Andy W1AWB


I'd think the 40673 mosfets harder to find though easy to substitute.

The ZTX330 is generic and a 2n3904, 2n2222 or similar should
work fine. For the 2n5950 I'd use a MPF102, 2n3819 or J310 fet as
those are easy to get. The transistors used are in non critical
circuits so substitutions should easily work.

Generally speaking the transistors and IC used reflects those
available to the author and reasonable substitutions will work
with no degradation.

The only parts that require care are the MAV-11 MIMICs and the SBL-3
as they helps define many of the modified recievers desired
characteristics.

Allison

These folks have a decent supply of 40673s. They advertise being
"Leaders on the trailing edge of technology". I don't know what their
onesy - twosey policy is, having never done business with them.
http://www.rocelec.com/

Also, search for "NTE" equivalents.

Russ

On Wed, 08 Mar 2006 09:56:37 -0500, Andy Bullington wrote:

Boy have I learned a lot on this little search...thanks to you guys. NTE
lists the NTE 222 as equivalent to the 40673 and Parts Express has them
for just under 9 bucks each. RF Parts has the 40673 for about $7. "Russ"

Thats a high price for a dual-gate MOSFET. You can buy more modern
devices for a much lower price. The BF981 and BF961 make excellent
RF and IF amplifiers. If you shop around, you can get them for
less than a dollar. Surface mount devices like the the BF996S are
well under a dollar, even from notoriously expensive suppliers
like Maplin. http://www.maplin.co.uk

73, Ed. EI9GQ.

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