[Collins] FD100 Diode data sheet

[jefferis at antelecom.net]

Once again, thanks for the info Jerry. I have 3 versions of
30L-1 manual. In the 8th edition, 15 July 1966, CR17,18, and
19 are still shown as 1N458. In the 11th edition, 15 June
1973, these are all FD100s. The update/change page in
section 7 of the '73 edition says: "Diodes CR17,CR18, and
CR19 were changed from type 1N458 to type FD100 to improve
rf detection. If any, or all, of these diodes are replaced,
it is reommended that type FD100 be used". 

I agree, the 1N458s were not great diodes for the
application. The FD100 is interesting from a historical
perspective because it was the first "planar" diode,
introduced in 1960. Fairchild billed it as a fast recovery
diode with "normal" conductance. They also offered an FD300
that was their "ultra-fast recovery", low conductance diode.
I tossed a complete 1970 Fairchild semiconductor data book
some years ago. At the time I thought I would never have a
use for it. Oh well. I have not been able to find much cross
reference data, and the Federal Stock system references to
the FD100 do not show that there were any competitive
substitutes ordered by the Feds.

Based on your input, it looks like the 1N4149 might be a
better match to the FD100 based on junction capacitance at
the test condition. Off hand, I don't think Schottky diodes
would be right in in the tuning bridge, but might be fine in
the  ALC circuit. It would be interesting to get the FD100
characteristic curves.

73, Bob KF6BC


----- Original Message Follows -----
From: "Dr. Gerald N. Johnson" <geraldj at storm.weather.net>
To: collins at mailman.qth.net
Subject: Re: [Collins] FD100 Diode data sheet
Date: Fri, 06 Feb 2009 21:40:57 -0600

>On Fri, 2009-02-06 at 15:36 -0800, Robert Jefferis wrote:
>> Hello,
>> 
>> Does anyone have a bona fide Fairchild data sheet on the
>> FD100 diode   that they would be willing to copy or
>> share? This was used in the   later 30L-1s. I have a
>> pretty good idea of its characteristics, and i   think
>that a 1N4148 would be a reasonable substitute. I would
>> just   like to have the original data in my archive.
>> Internet searches have   been fruitless and direct
>> contact with Fairchild was no help. Thanks. 
>> Bob, KF6BC 
>
> Where did they use the FD100? The 5th ed manual Dated June
>1962 I've downloaded shows a 1N252 and a 1N458 other than
>the power rectifiers. I don't think either one of those was
>stellar in performance. One service bulletin calls for
>using a 1N458 in place of a 1N252.
>
>I did not find a FD100 data sheet in my box of Fairchild
>data, but I did find a July 1970 condensed catalog.
>
>For the FD100 it says Bv = 75 volts. Ir = 100 na at 50
>volts reverse. If 10 ma at 1 volt. 2.0 pf capacitance and
>Trr 4ns. D0-7 package.
>
>1N252: Bv = 25 volts. Ir = 100 na @ 5 volts. If = 10 ma @ 1
>volt. Cap not stated. Trr 4.0 ns, DO-7 package.
>
>1N458: Bv 150 volts. Ir = 25 na @ 125 volts. If 7 ma @ 1 v.
>Cap not stated. DO-7 package.
>
>1N914: Bv 100 v. Ir 25 na @ 20 v. If 10 ma @ 1v. C 4.0 pf.
>Trr 4.0 ns, DO-7. equivalent 1N4148.
>
>1N916: Bv 100 v. Ir 25 na @ 20 v. If 10ma @ 1v. Cap 2.0 pf.
>Trr 4.0 ns, DO-7, equivalent 1N4149.
>
>1N4148 same as 1N914 except DO-35 package.
>
>1N4149 same as 1N916 except DO-35 package.
>
>1N4454:  Bv 75 v. Ir 100 na @ 50v. If  10 na @ 1 v. Cap 2.0
>pf. Trr 4.0 ns, DO-35 package, equivalent to 1N3064 in DO-7
>package. Looks like the exact same thing as a FD100. At
>least according to Fairchild in 1970. And costs a whopping
>3 cents from Mouser. The 1N4148 is a cheaper, 2 whole
>cents. -- 
>73, Jerry, K0CQ, Technical Advisor to the CRA
>All content copyright Dr. Gerald N. Johnson, electrical
>engineer
>
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