Andy wrote:
It looks like some of the SM 3-pin diodes D10, D9, etc have failed. I was
only testing with a 100 watts although it was with a very high SWR at the
time

Do I have to go to SGC for the diodes or is there a replacement that I can
use instead?

My SGC-230 manual says those are 1N4148 high speed
switching diodes which are one of the most popular
diodes of all time. They should be readily available
almost anywhere.
--
73, Cecil http://www.w5dxp.com

Cecil,

I had a look at the 1N4148, they are 2-pin.

The diodes in mine are Surface mount 3-pin.

Are the 1N4148 diodes for the old version board, before year 2000?

My board is the newer version, after year 2000

73 Andy


"Cecil Moore" wrote in message
. ..
Andy wrote:
It looks like some of the SM 3-pin diodes D10, D9, etc have failed. I was
only testing with a 100 watts although it was with a very high SWR at the
time

Do I have to go to SGC for the diodes or is there a replacement that I
can use instead?

My SGC-230 manual says those are 1N4148 high speed
switching diodes which are one of the most popular
diodes of all time. They should be readily available
almost anywhere.
--
73, Cecil http://www.w5dxp.com

Andy wrote:
Cecil,

I had a look at the 1N4148, they are 2-pin.

The diodes in mine are Surface mount 3-pin.

Are the 1N4148 diodes for the old version board, before year 2000?

Yes, my manual is copyright 1994.

My board is the newer version, after year 2000

What does your schematic say about those diodes?
--
73, Cecil http://www.w5dxp.com

This is the problem that I have got with my SG-230.
I purchased it new myself. My PCB board is an Q50102000-E. it is what they
call the newer version, after the year 2000.

My manual is a Revised: November 2000. The Document number for the
schematic, Q30102000E Rev: A Dated February 17, 1992. It looks to me to be
the wrong schematic for my PCB board. Maybe some one might know if it is or
not or have the correct one that they can send me?

All it says about the diodes is that they are either D5, D7, D9 etc. It
doesn't say what they are.

73 Andy



"Cecil Moore" wrote in message
. ..
Andy wrote:
Cecil,

I had a look at the 1N4148, they are 2-pin.

The diodes in mine are Surface mount 3-pin.

Are the 1N4148 diodes for the old version board, before year 2000?

Yes, my manual is copyright 1994.

My board is the newer version, after year 2000

What does your schematic say about those diodes?
--
73, Cecil http://www.w5dxp.com

Andy wrote:
My manual is a Revised: November 2000. The Document number for the
schematic, Q30102000E Rev: A Dated February 17, 1992. It looks to me to be
the wrong schematic for my PCB board. Maybe some one might know if it is or
not or have the correct one that they can send me?

This one is copyrighted Nov. 2000

www.sgcworld.com/Publications/Manuals/230man.pdf

All it says about the diodes is that they are either D5, D7, D9 etc. It
doesn't say what they are.

Yes, it doesn't say but if it were me, I would replace the
blown diodes with 1N4148's (assuming discrete diodes will
fit in the SMD pad space).
--
73, Cecil http://www.w5dxp.com

Yes, that is exactly the same manual as mine.
How would I connect the 1N4148 2-pin to the 3 pads that are under the SM
3-pin diodes, will this even work?

If it is possible I would have to mount them vertical.

73 Andy


"Cecil Moore" wrote in message
. ..
Andy wrote:
My manual is a Revised: November 2000. The Document number for the
schematic, Q30102000E Rev: A Dated February 17, 1992. It looks to me to
be the wrong schematic for my PCB board. Maybe some one might know if it
is or not or have the correct one that they can send me?

This one is copyrighted Nov. 2000

www.sgcworld.com/Publications/Manuals/230man.pdf

All it says about the diodes is that they are either D5, D7, D9 etc. It
doesn't say what they are.

Yes, it doesn't say but if it were me, I would replace the
blown diodes with 1N4148's (assuming discrete diodes will
fit in the SMD pad space).
--
73, Cecil http://www.w5dxp.com

Andy wrote:
Yes, that is exactly the same manual as mine.
How would I connect the 1N4148 2-pin to the 3 pads that are under the SM
3-pin diodes, will this even work?

I'm pretty sure it would work if you get the pads right.
One is probably grounded. One is probably the cathode.
One is probably the anode. You should be able to figure
out which is which using a digital ohm-meter.
--
73, Cecil http://www.w5dxp.com

All it says about the diodes is that they are either D5, D7, D9 etc. It
doesn't say what they are.

Yes, it doesn't say but if it were me, I would replace the
blown diodes with 1N4148's (assuming discrete diodes will
fit in the SMD pad space).

I wonder whether these diodes might not be MMBD4148 or some such?
These are 1N4148-type fast switching diodes in an 3-pin SOT323
surface-mount package.

Mouser and Digi-Key carry several variants of these. The MCC versions
are $.10-$.15 each in onesies and are good to 75V, 150 mA. The Diodes
INc. versions are around half a buck each in onesies, and are good to
75V, 200 mW. I'm not sure whether you'd want apples, or oranges :-)

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

In my SG-230, it says 5DL on the top of diode. Don't know if that is an ID:
code of sorts.

73 Andy


"Dave Platt" wrote in message
...
All it says about the diodes is that they are either D5, D7, D9 etc. It
doesn't say what they are.

Yes, it doesn't say but if it were me, I would replace the
blown diodes with 1N4148's (assuming discrete diodes will
fit in the SMD pad space).

I wonder whether these diodes might not be MMBD4148 or some such?
These are 1N4148-type fast switching diodes in an 3-pin SOT323
surface-mount package.

Mouser and Digi-Key carry several variants of these. The MCC versions
are $.10-$.15 each in onesies and are good to 75V, 150 mA. The Diodes
INc. versions are around half a buck each in onesies, and are good to
75V, 200 mW. I'm not sure whether you'd want apples, or oranges :-)

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!