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Old August 18th 08, 02:12 AM posted to rec.radio.amateur.homebrew
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Default Wanted, Diodes

I am looking for a few (10) diodes 1N270...It is a germanium and used
in Double Balanced mixers in SSB generation..Most suppliers have a $25
to $50 min order and I don`t care for that.. thanks Harold W4PQW
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Old August 18th 08, 03:31 AM posted to rec.radio.amateur.homebrew
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Default Wanted, Diodes


"mrhaney" wrote in message
...
I am looking for a few (10) diodes 1N270...It is a germanium and used
in Double Balanced mixers in SSB generation..Most suppliers have a $25
to $50 min order and I don`t care for that.. thanks Harold W4PQW


Hi Harold. I can supply your needs, but for info, I have never. in a lot of
years, called on MiniCircuits Labs (MO) for a small order and not have them
waive the minimum order charge if needed. VERY nice folks to work with and
they make better balanced mixers than you will. They have some black magic
in their ferrite department.

W4ZCB


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Old August 18th 08, 03:50 AM posted to rec.radio.amateur.homebrew
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Default Wanted, Diodes


"mrhaney" wrote in message
...
I am looking for a few (10) diodes 1N270...It is a germanium and used
in Double Balanced mixers in SSB generation..Most suppliers have a $25
to $50 min order and I don`t care for that.. thanks Harold W4PQW


Have you tried Dans Small Parts? Are hot carrier diodes
an acceptable substitute for that application?

73

Pete


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Old August 18th 08, 04:09 PM posted to rec.radio.amateur.homebrew
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Default Wanted, Diodes

On Aug 17, 9:12*pm, mrhaney wrote:
I am looking for a few (10) diodes 1N270...It is a germanium and used
in Double Balanced mixers in SSB generation..Most suppliers have a $25
to $50 min order and I don`t care for that.. thanks * Harold W4PQW


Are you trying to reproduce something from a 60's handbook? I remember
them speccing 1N270's but that's because those were the parts people
had in the junkboxes back then. There is nothing at all magic about
germanium here. The silicon diodes will require slightly more drive
voltage to switch but that's not a big deal as you always drive them
way into saturation anyway.

NTE109 is the ECT/NTE number for a their medium-voltage germanium
replacement, officially listed in the NTE sub book, and Mouser and
maybe even your local radio/TV repairman would have some. Mouser has
no minimum order.

You will have much better luck using 1N914's or 1N4148's or even
better a real matched DBM from Minicircuits et al. "Experimental
Methods in RF Design" has a lot of good scoop on mixers that goes way
beyond anything in a 60's ARRL handbook.

Tim N3QE
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Old August 19th 08, 11:13 PM posted to rec.radio.amateur.homebrew
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Default Wanted, Diodes

On Aug 17, 9:12 pm, mrhaney wrote:
I am looking for a few (10) diodes 1N270...It is a germanium and used
in Double Balanced mixers in SSB generation..Most suppliers have a $25
to $50 min order and I don`t care for that.. thanks Harold W4PQW


Hey Harold:

Try your luck with this guy:

http://www.angelfire.com/electronic2/index1/index.html

takes paypal has tonnes of them in stock and only charges

$3.95 for shipping and handling for an order like yours

The shipping cost more than the parts but there's no

minimum order.

73 OM

N8ZU


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Old August 23rd 08, 08:39 PM posted to rec.radio.amateur.homebrew
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Default Wanted, Diodes

On Aug 17, 6:12*pm, mrhaney wrote:
I am looking for a few (10) diodes 1N270...It is a germanium and used
in Double Balanced mixers in SSB generation..Most suppliers have a $25
to $50 min order and I don`t care for that.. thanks * Harold W4PQW


So after all that, any hints on what the original project was? Even
in the 1970s people were speccing matched silicon diodes (e.g. 1N914)
or hot carrier diodes (e.g. 5082-2800) for mixers.

Laura Halliday VE7LDH "Non sequitur. Your ACKS are
Grid: CN89mg uncoordinated."
ICBM: 49 16.05 N 122 56.92 W - Nomad the Network Engineer
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Old August 25th 08, 02:14 PM posted to rec.radio.amateur.homebrew
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Default Wanted, Diodes

On Aug 23, 3:39*pm, laura halliday wrote:
On Aug 17, 6:12*pm, mrhaney wrote:

I am looking for a few (10) diodes 1N270...It is a germanium and used
in Double Balanced mixers in SSB generation..Most suppliers have a $25
to $50 min order and I don`t care for that.. thanks * Harold W4PQW


So after all that, any hints on what the original project was? Even
in the 1970s people were speccing matched silicon diodes (e.g. 1N914)
or hot carrier diodes (e.g. 5082-2800) for mixers.


At least two volumes of "Single Side Band for the Radio Amateur" and
many ARRL handbooks from the 60's show 1N270's used in balanced
mixers.

It was a jellybean of the time, it's odd that someone would not
realize it and slavishly want to use it rather than something more
readily available (and performance-wise far superior) today. Probably
the same guys who insist on carbon-composition resistors everywhere
today too :-).

There are some things that appear in old construction articles that
are worth finding. For example, the BC-453/454/455's tuning capacitors
and drive mechanism are truly superb and I still keep my eyes open for
them today :-).

Tim.
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Old August 26th 08, 07:10 AM posted to rec.radio.amateur.homebrew
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Default Wanted, Diodes

I have 1N34A's... will they do?

Cheers,
__
Gregg

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Old August 26th 08, 04:30 PM posted to rec.radio.amateur.homebrew
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Default Wanted, Diodes

On Aug 25, 6:14 am, Tim Shoppa wrote:
On Aug 23, 3:39 pm, laura halliday wrote:

On Aug 17, 6:12 pm, mrhaney wrote:


I am looking for a few (10) diodes 1N270...It is a germanium and used
in Double Balanced mixers in SSB generation..Most suppliers have a $25
to $50 min order and I don`t care for that.. thanks Harold W4PQW


So after all that, any hints on what the original project was? Even
in the 1970s people were speccing matched silicon diodes (e.g. 1N914)
or hot carrier diodes (e.g. 5082-2800) for mixers.


At least two volumes of "Single Side Band for the Radio Amateur" and
many ARRL handbooks from the 60's show 1N270's used in balanced
mixers.

It was a jellybean of the time, it's odd that someone would not
realize it and slavishly want to use it rather than something more
readily available (and performance-wise far superior) today. Probably
the same guys who insist on carbon-composition resistors everywhere
today too :-).

There are some things that appear in old construction articles that
are worth finding. For example, the BC-453/454/455's tuning capacitors
and drive mechanism are truly superb and I still keep my eyes open for
them today :-).

Tim.


Indeed. I have several old ARRL and RSGB Handbooks and a
number of older references (including Single Sideband for the
Radio Amateur).

You can see the fashions change. At one time the cool part to
use was the 7360 beam deflection mixer tube; at other times the
challenge was to see how many 40673 MOSFETs you could use
in a single radio. Many of these designs are difficult to reproduce
now.

I'll see your BC-455 tuning capacitor and raise you an Eddystone
dial. :-)

You can make nice radios by applying the right technology to
the problem. My recipe for a stable VFO nowadays is a
postage-stamp size surface mount board mummified in bubble
wrap and stuck to the end of a good, solid air variable capacitor.

Laura Halliday VE7LDH "Non sequitur. Your ACKS are
Grid: CN89mg uncoordinated."
ICBM: 49 16.05 N 122 56.92 W - Nomad the Network Engineer
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Old August 26th 08, 06:46 PM posted to rec.radio.amateur.homebrew
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Posts: 263
Default Wanted, Diodes

On Aug 26, 11:30*am, laura halliday wrote:
Indeed. I have several old ARRL and RSGB Handbooks and a
number of older references (including Single Sideband for the
Radio Amateur).

You can see the fashions change. At one time the cool part to
use was the 7360 beam deflection mixer tube; at other times the
challenge was to see how many 40673 MOSFETs you could use
in a single radio. Many of these designs are difficult to reproduce
now.


What's amazing is that some of the SSB rigs appearing in the 60's in
the pages of QST use not one, not two, but three 7360's :-).

40673's were also used with wild abandon. If someone wants an honest-
to-goodness 40673 they can pay $15 for a NTE221 in a metal can, but
most experimenters would use a BF998, obviously a different package
but same function.

I'll see your BC-455 tuning capacitor and raise you an Eddystone
dial. :-)

You can make nice radios by applying the right technology to
the problem. My recipe for a stable VFO nowadays is a
postage-stamp size surface mount board mummified in bubble
wrap and stuck to the end of a good, solid air variable capacitor.


The brass-screw-in-a-solenoid is something I just tried in my
reproduction of the MMR-40 and I am very impressed with its stability
and mechanical simplicity as a PTO. A similar but not identical
mechanical design is used in the WA6OTP PTO, I haven't tried it yet.

Tim.
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