[Boatanchors] Linear Tuning in VFOs -- SFW and SFL Variable Capacitors

[Nick England]

Well, there are always exceptions…
TMC used capacitor tuned oscillators with a cam mechanism to provide
linearity.
I believe the Heathkit SB-series master oscillators were capacitor-tuned as
was the Hallicrafters SX-115.
Things from dim memory so probably subject to correction.
Nick K4NYW

On Mon, Sep 5, 2022 at 7:51 PM Al Parker <anchor at ec.rr.com> wrote:

> Hi Bill,
>         It's cuz some have PTO (permeability tuned) oscillators (usually a
> slug
> moving thru and inductor.) and some have capacitive tuned osc.    Drake
> has PTO's mostly, as does Collins, SP-xxx's, most if not all Halli's use
> a variable capacitor.
> 73,
>
> Al, W8UT
> www.boatanchors.org
> www.hammarlund.info
>
> "There is nothing -- absolutely nothing -- half so much
> worth doing as simply messing about in boats"
> Ratty, to Mole
>
> On 9/5/2022 1:11 PM, Bill Meara via Boatanchors wrote:
> > Drake 2-B!  HT-37!  SP receivers!  HQ-100s   Why do some rigs have nice,
> linear tuning, while others havethe frequencies bunched up at one end of
> the tuning range? Enquiring hams want to know!
> >
> https://soldersmoke.blogspot.com/2022/09/why-do-some-vfos-tune-more-linearly.html
> >
> > 73  Bill N2CQR
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-- 
Nick England K4NYW
www.navy-radio.com