[Elecraft] 1N4007 diode question?

[Eddy Avila]

SN 3345

Does Radio Shack sell a good-quality 1N4007 diode I can use in the KSB2
adapter?

Don't ask...I really screwed up this time!

Tnx....73



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[Denis Dimick]

No, RS is not going to have this diode.. I lost one when building my K1,
so I know..

Post by Eddy Avila
SN 3345
Does Radio Shack sell a good-quality 1N4007 diode I can use in the KSB2
adapter?
Don't ask...I really screwed up this time!
Tnx....73
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[Bob Lewis (AA4PB)" (Bob Lewis (AA4PB))]

The 1N4007 is rated 1000V @ 1A. The 1N4005 is rated 600V @ 1A. The
1N4005 should work just fine in this application and it is a stock
Radio Shack item.

[Don Brown]

Hi

Do not sub the 1n4007 with a lower voltage diode. These diodes are used as
pin diodes to switch RF. The 1n4007 is the only one in the series that have
the pin characteristics.

Don



----- Original Message -----
From: "Bob Lewis (AA4PB)" <***@staffnet.com>
To: <***@mailman.qth.net>
Sent: Sunday, April 06, 2003 2:23 PM
Subject: Re: [Elecraft] 1N4007 diode question?

Post by Bob Lewis (AA4PB)" (Bob Lewis (AA4PB))
1N4005 should work just fine in this application and it is a stock
Radio Shack item.
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[Bob Lewis (AA4PB)" (Bob Lewis (AA4PB))]

Post by Don Brown
Do not sub the 1n4007 with a lower voltage diode.

Could be. All the Fairchild 1N400x series however use the very same
specification sheet and the only difference shown is the voltage. If
we are working with a non-specified parameter, I wonder if there is
also a difference between manufacturers. Perhaps Wayne can provide
some additional info.

[Don Brown]

Hi

The 1n4000 series of diodes are general purpose rectifier diodes designed
for low frequency use primarily 60 Hz power supplies. The construction is
the same for the series except the 1n4007. The lower voltage diodes are
basic PN junctions and would not work as a RF switch. The 1n4007 however has
an extra intrinsic (undoped) layer forming the P-I-N junction. This is, I
would guess, is to get the 1Kv PIV rating but it also allows the 1n4007 to
work as a RF switch like a true PIN diode The RF characteristics are not
specified on this diode because it is not designed to do this type of work
it just happened to work out that way and they are very cheap. True PIN
diodes work better than the 1n4007 but are more expensive and not as readily
available. Elecraft has designed the RF switching to work with the 1n4007
and making substations of different diodes may not work. Other 1n4000 series
defiantly do not have the PIN structure so they will not work.

Don Brown
KD5NDB


----- Original Message -----
From: "Bob Lewis (AA4PB)" <***@staffnet.com>
To: <***@mailman.qth.net>
Sent: Sunday, April 06, 2003 7:55 PM
Subject: Re: [Elecraft] 1N4007 diode question?

Post by Bob Lewis (AA4PB)" (Bob Lewis (AA4PB))

Post by Don Brown
Do not sub the 1n4007 with a lower voltage diode.

Could be. All the Fairchild 1N400x series however use the very same
specification sheet and the only difference shown is the voltage. If
we are working with a non-specified parameter, I wonder if there is
also a difference between manufacturers. Perhaps Wayne can provide
some additional info.

[Don Brown]

Hi

Try Mouser or Digikey. If you just need one or two let me know and I will
mail them to you.

Don Brown
KD5NDB


----- Original Message -----
From: "Eddy Avila" <***@hotmail.com>
To: <***@mailman.qth.net>
Sent: Sunday, April 06, 2003 12:16 PM
Subject: [Elecraft] 1N4007 diode question?

Post by Eddy Avila
SN 3345
Does Radio Shack sell a good-quality 1N4007 diode I can use in the KSB2
adapter?
Don't ask...I really screwed up this time!
Tnx....73
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[Stuart Rohre]

Another good source, is Dan's Small Parts and Kits, (on web).
72,
Stuart K5KVH

[Sverre Holm - LA3ZA]

I would double check that the 1N4005 can be substitued for the 1N4007
here.

If I remember right, the 1N4007 is used as a switching diode in the
KSB2, not as a rectifier, so one should make sure the 1N4005 has the
same switching behavior.


Sverre
LA3ZA
www.qsl.net/la3za

-----Original Message-----
Sent: 6. april 2003 21:23
Subject: Re: [Elecraft] 1N4007 diode question?
1A. The 1N4005 should work just fine in this application and
it is a stock Radio Shack item.
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[Lyle Johnson]

1N4005 should work just fine...

The 1N4007 is used as a poor-man's PIN diode, I believe, in this
application. The voltage isn't important, but the diode internal physics
are. I believe you want a 1N4007 for it to work properly.

73,

Lyle KK7P

[k***@juno.com]

I've been reading with interest the comments about substituting a 1N4007
with a 1N4005. When I built my K2 I quickly needed a 1N4007 (I now
forget the reason) and got a 1N4005 from the local RS store. I installed
it and it's still there.

As I recall, the location was on the rear of the RF board (in D2, D3, or
D4). After many hours of operation, I haven't noticed any problems in
T-R switching that might be due to this substitution.

73, de Earl, K6SE

[Don Brown]

Hi

Pin diodes act more like variable resistors than diodes at RF frequencies.
So think of D2, D3 and D4 in series when turned on and open circuits when
turned off. If you replaced one of the diodes with a non PIN type (1n4005)
then the other diodes may still provide enough isolation when in receive but
I would still replace the diode with the correct type (1n4007) that has the
PIN internal construction. Wayne may want to explain this more fully as I am
not an expert on this and I am getting my information from several internet
sites and the ARRL Handbook.

Don Brown
KD5NDB


----- Original Message -----
From: <***@juno.com>
To: <***@mailman.qth.net>
Sent: Monday, April 07, 2003 4:01 PM
Subject: Re: [Elecraft] 1N4007 diode question?

Post by k***@juno.com
I've been reading with interest the comments about substituting a 1N4007
with a 1N4005. When I built my K2 I quickly needed a 1N4007 (I now
forget the reason) and got a 1N4005 from the local RS store. I installed
it and it's still there.
As I recall, the location was on the rear of the RF board (in D2, D3, or
D4). After many hours of operation, I haven't noticed any problems in
T-R switching that might be due to this substitution.
73, de Earl, K6SE

[Don Brown]

Hi All

Ok I must amend my statement on the 1n4007. My curiosity got me to thinking
so an experiment was in order. I went out and bread boarded a circuit. It
looks like the entire family of 1n4000 exhibit the PIN characteristics. I
tried the 1n4001, 1n4002 and 1n4007 at different frequencies from 3 to 40
mHz at 5 volts Pk to Pk and they all work the same with a switching current
of about 8 ma. Just for grins I tried a 1n4148 and it does not work at all.
It rectifies the RF as you would expect. The 1n4007 passes the RF without
distorting it at all.

There are several articles on the web that mention that the 1n4007 is the
only one in the series that will work as a PIN diode but my tests seem to
discount that. So will a 1n4005 diode work in place of the 1n4007 in the K2
possibly, but I would still go back and use the proper part if possible.

Don Brown
KD5NDB


----- Original Message -----
From: "Don Brown" <***@msn.com>
To: <***@mailman.qth.net>
Sent: Monday, April 07, 2003 5:11 PM
Subject: Re: [Elecraft] 1N4007 diode question?

Post by Don Brown
Hi
Pin diodes act more like variable resistors than diodes at RF frequencies.
So think of D2, D3 and D4 in series when turned on and open circuits when
turned off. If you replaced one of the diodes with a non PIN type (1n4005)
then the other diodes may still provide enough isolation when in receive but
I would still replace the diode with the correct type (1n4007) that has the
PIN internal construction. Wayne may want to explain this more fully as I am
not an expert on this and I am getting my information from several internet
sites and the ARRL Handbook.
Don Brown
KD5NDB
----- Original Message -----
Sent: Monday, April 07, 2003 4:01 PM
Subject: Re: [Elecraft] 1N4007 diode question?

Post by k***@juno.com
I've been reading with interest the comments about substituting a 1N4007
with a 1N4005. When I built my K2 I quickly needed a 1N4007 (I now
forget the reason) and got a 1N4005 from the local RS store. I installed
it and it's still there.
As I recall, the location was on the rear of the RF board (in D2, D3, or
D4). After many hours of operation, I haven't noticed any problems in
T-R switching that might be due to this substitution.
73, de Earl, K6SE

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[rolf heidenborg]

Hi Earl,
I think these diodes in the serie are built up of bricks and the more
bricks the more reverse voltage can they take. 1N4000 fewest bricks and
1N4007
the most.
I also think they can be used as cap diodes.
I remember we had that 1N4007 in a noise generating device which we
used to see how well our computersystem could withstand noise.
At times this generator did not perform up to the point where the
noise injected should make the computersystem fail and then we were
not able to meassure with ohmmeter if these diodes were bad or not.
They looked normal compared with a new diode.
Despite the good reading - after having replaced these diodes,there
were a lot of them,the generator worked well again until next time
when it failed.
I guess these diodes were driven a bit too hard in that device.
73 Rolf sm0cls


-----Ursprungligt meddelande-----
Fran: elecraft-***@mailman.qth.net
[mailto:elecraft-***@mailman.qth.net]For ***@juno.com
Skickat: den 7 april 2003 23:01
Till: ***@mailman.qth.net
Amne: Re: [Elecraft] 1N4007 diode question?


I've been reading with interest the comments about substituting a 1N4007
with a 1N4005. When I built my K2 I quickly needed a 1N4007 (I now
forget the reason) and got a 1N4005 from the local RS store. I installed
it and it's still there.

As I recall, the location was on the rear of the RF board (in D2, D3, or
D4). After many hours of operation, I haven't noticed any problems in
T-R switching that might be due to this substitution.

73, de Earl, K6SE
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Elecraft mailing list: ***@mailman.qth.net
You must be a list member to post to the list.
Postings must be plain text (no HTML or attachments).
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[Ron D'Eau Claire]

I've used a great many silicon diodes as RF switches. That use goes way =
back
before PIN diodes. All one needs is sufficient bias to keep the diode =
either
conducting or not conducting, as you desire.=20

Isn't the unique feature of a PIN diode its ability to act as a variable
resistor to RF as the bias is varied, rather than rectifying he RF? That
capability isn't used in a simple T/R switch like, say, in the KPA100.=20

I just did a quick check and came up with the "CQ Antenna Roundup" book
published in 1963 (FORTY years ago!) in which Don Stoner, W6TNS and L.A.
Earnshaw, ZL1AAX describe the use of silicon diodes as RF switches with
examples in a variety of applications. They were using early silicon =
power
rectifiers in this application.

Ron AC7AC
K2 # 1289

-----Original Message-----
From: elecraft-***@mailman.qth.net =
[mailto:elecraft-***@mailman.qth.net]
On Behalf Of Don Brown

...My curiosity got me to thinking so an experiment was in order. I went =
out
and bread boarded a circuit. It looks like the entire family of 1n4000
exhibit the PIN characteristics. I tried the 1n4001, 1n4002 and 1n4007 =
at
different frequencies from 3 to 40 mHz at 5 volts Pk to Pk and they all =
work
the same with a switching current of about 8 ma. Just for grins I tried =
a
1n4148 and it does not work at all. It rectifies the RF as you would =
expect.
The 1n4007 passes the RF without distorting it at all.

There are several articles on the web that mention that the 1n4007 is =
the
only one in the series that will work as a PIN diode but my tests seem =
to
discount that. So will a 1n4005 diode work in place of the 1n4007 in the =
K2
possibly, but I would still go back and use the proper part if possible.

Don Brown
KD5NDB

[John, KI6WX]

A pin diode can actually block RF voltages that are higher than the reverse
bias. This is quite true of the 1N4007's used in the KPA100 T-R switch.
They would probably work fine with only 20-30 volts of reverse bias. With
the 100 volt bias used on them, you have even more margin, especially when
driving non 50 ohm loads.
-John
KI6WX

----- Original Message -----
From: "Ron D'Eau Claire" <***@easystreet.com>


I've used a great many silicon diodes as RF switches. That use goes way back
before PIN diodes. All one needs is sufficient bias to keep the diode either
conducting or not conducting, as you desire.

Isn't the unique feature of a PIN diode its ability to act as a variable
resistor to RF as the bias is varied, rather than rectifying he RF? That
capability isn't used in a simple T/R switch like, say, in the KPA100.

[k***@juno.com]

Ron, AC7AC wrote:

"Isn't the unique feature of a PIN diode its ability to act as a variable
resistor to RF as the bias is varied, rather than rectifying he RF?"
==========
I don't know how "rectifying the RF" got into this subject, because it
doesn't appear to me to have anything to do with the question. D2, D3
and D4 are all forward biased by a solid (not varying) +8 VDC in the
receive mode, while D1 and D5 are forward biased in the transmit mode.
An RF signal has nothing to do with this.

The low-level RF signal present in this circuit (in either xmt or rcv)
certainly will not overcome the 8 volts of bias on the diodes and will
not even come close to exceeding the 600-volt peak reverse rating of a
1N4005.

73, de Earl, K6SE

[Guy Olinger, K2AV]

May it not be a matter that the DESIGN of the 1N4007 relates to the application properly or best, while the actual comparative MEASUREMENTS or FAILURE RATE would be difficult to come by in a casual examination?

Or said another way, use 1N4004 if you want, but YMMV...or it may not, depending on whether you have stroked the Blarney Stone recently.

73, Guy.

Date: 2003/04/07 Mon PM 11:26:03 EDT
Subject: RE: [Elecraft] 1N4007 diode question?
I've used a great many silicon diodes as RF switches. That use goes way back
before PIN diodes. All one needs is sufficient bias to keep the diode either
conducting or not conducting, as you desire.
Isn't the unique feature of a PIN diode its ability to act as a variable
resistor to RF as the bias is varied, rather than rectifying he RF? That
capability isn't used in a simple T/R switch like, say, in the KPA100.
I just did a quick check and came up with the "CQ Antenna Roundup" book
published in 1963 (FORTY years ago!) in which Don Stoner, W6TNS and L.A.
Earnshaw, ZL1AAX describe the use of silicon diodes as RF switches with
examples in a variety of applications. They were using early silicon power
rectifiers in this application.
Ron AC7AC
K2 # 1289
-----Original Message-----
On Behalf Of Don Brown
...My curiosity got me to thinking so an experiment was in order. I went out
and bread boarded a circuit. It looks like the entire family of 1n4000
exhibit the PIN characteristics. I tried the 1n4001, 1n4002 and 1n4007 at
different frequencies from 3 to 40 mHz at 5 volts Pk to Pk and they all work
the same with a switching current of about 8 ma. Just for grins I tried a
1n4148 and it does not work at all. It rectifies the RF as you would expect.
The 1n4007 passes the RF without distorting it at all.
There are several articles on the web that mention that the 1n4007 is the
only one in the series that will work as a PIN diode but my tests seem to
discount that. So will a 1n4005 diode work in place of the 1n4007 in the K2
possibly, but I would still go back and use the proper part if possible.
Don Brown
KD5NDB
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73, Guy
K2AV