[Elecraft] K3: IF output buffer gain modification

[Ian White GM3SEK]

Dave G4AON wrote:
>
>Bill W4ZV wrote:
>
>>When the mod was first published I asked:
>>"Just checking to see if this is a typo. 13K or 12K?"
>>
>>Bob Friess N6CM (the 1st mixer designer) replied:
>>"13K is a standard 5% value and is correct."
>>
>>I took the 5% tolerance to mean the value is somewhat critical.
>>

>There is about 0.2 dB difference between using one value or the other,
>depending on the accuracy of your model.
>

13K is a standard value in the E24 series, which covers a full decade in 
24 steps. Each step is about 10% above the previous value, so E24 
resistors have to be manufactured with a tolerance of 5% or better.

http://www.logwell.com/tech/components/resistor_values.html

But *standard* values aren't the same as the most-used *common* values. 
The ones most used are the well known E6 series (1.0, 1.5, 2.2 etc) or 
the E12 series (1.0, 1.2, 1.5, 1.8, 2.2 etc).

Most RF circuits don't operate within 5% margins, so they can get along 
fine with E6 and E12 values.


-- 

73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek