[time-nuts] Dead 5065A - Some comments - Some questions... (III)

[Magnus Danielson]

Hi Paul,

On 2020-08-26 17:11, paul swed wrote:
> Ulf I was thinking the 137 Hz was injected differently. But yes its a
> varicap on the 5 Mhz signal. Still that same effect can be accomplished in
> the PLL feedback loop. I would simply go try these things but can not hack
> my one and only 5065. Its working just fine.
Arn't you curious about making it work finer? :)
> A question
> The 137 is injected at 5Mhz isn't it multiplied to a FM swing of 2466 Hz at
> 90 MHz? Granted close in sidebands would still contain 137 Hz.

No, the modulation frequency would still be the same, but the modulation
width scale up as the carrier scales up. Thus, the frequency deviation
scales up.

As you are a ham, I will make you recall the old days. In the old days
as people aimed to reach the 70 cm band, they used their 2 m equipment
and trippled the frequency. This makes the 144 MHz go to 432 MHz, the 25
kHz deviation go to 75 kHz deviation and the modulated voice stays the
same pitch as it had on 144 MHz and does not pitch up about 1.5 octaves.

Cheers,
Magnus