[Elecraft] Field Day rig experience

[Wes Stewart]

Certainly not to disparage the K3(S) architecture (I have two of them) there is 
nothing inherently wrong with an up-conversion receiver, if modern hardware is used.

See: https://martein.home.xs4all.nl/pa3ake/hmode/g3sbi_intro.html

and my friend Cornell's, Star-10 transceiver. 
https://pdfs.semanticscholar.org/eb33/5c12858779a653d9b9b93ca20120aebb7616.pdf

Wes  N7WS


  On 6/13/2018 11:38 AM, WILLIE BABER wrote:
> Robert is talking about the crystal filters, also known as roofing filters now-days, that are typically placed after the first mixer (I mistakenly typed "ahead" but I meant "after" as Robert notes), though there is a post amp and NB before these filters in K2 and K3.
>
> The idea is that a crystal filter right after the first mixer gives high dynamic range because high selectivity comes before the receiver has developed stages of gain that otherwise could cause blocking or IMD, especially when selectivity is postponed to the second mixer while ignoring gain distribution in prior stages of the receiver.  This basic idea was popularized in Solid State Design for the Radio Amateur, and it was applied to Ten-Tec radios for decades (at a 9 mhz I-F).
>
> Roofing filter gets defined in relationship to Japanese radios that had up conversion 15 khz filters at the first I-F, and generally lower dynamic range as a result, (but you got all modes, general coverage, and optional crystal filters at the second I-F).
>
> Good for everyone radios.... but with lower dynamic range and phase noise from the early synthesizers.  This is why Ten-Tec radios were so popular among contesters, especially Omni V and VI (modified with a narrow cw filter at the first I-F).
>
> 73, Will, wj9b
>