Hello Zaba,
> Still my best wishes to you for 2020. I hope it will as
> productive as last year!
My best wishes to you in return:-)
I will continue for a while with the nerds series. There
are many more things to look at....
> Today I sampled some of your
> great nerds45-nerds49 YouTube-videos. I assume those
> have started at nerds01 (or in old HP-85 BASIC-terms:
> OPTIONBASE0 at nerds00?).
The first one was nerds1. I did not know how many
positions to reserve for the number;-)
> Do you mean to say that if I take a regular oscillator,
> and I put that through a quality frequency-doubler, that
> my phase-noise will be orders of magnitude better?
No, what I say is that a quality doubler will degrade
phase noise with the theoretical 6 dB and not more even
if you start with a very good oscillator.
> The reason for using 8 x J310 FET's in parallel, is that
> for averaging/lowering noise figure, like in the Javornik
> type 4 x BF998 preamps?
The multiplier runs at 1 W input power and to make the wide
band noise well above -174 dBm/Hz I need the output power
to be of a similar level. Many parallel transistors is for
the power handling. For 1 W output power I would need 5 W
DC power assuming an efficiency of 20%. The J310 is rated
250mW. I do not remember the details.
> P.S. It's at least six years ago that my WSE's negative
> rail voltage got defect. It is a shame that those boxes
> have been standing unused for such a long time. By-the-way
> is there any advantage in combining X-phase QRM-eliminators
> together with linrad. I assume it advantageous to start with
> a low as possible QRM/QRN level even with linrad. Anyway, it
> is time to repair the -15 V power supply for WSE.
If you have more than two antennas you could use phasing
to combine pairwise for a reduced level of qrm. Particularly
useful to have a small antenna with strong coupling to one
particular interference source and to use it with QRM eliminators
together with the main antennas. Then another small antenna
(small antenna is E-field probes or H-field probes) to eliminate
another local interference source. Finally combine main antennas
pair-wise with QRM eliminators until you have two signals only
that you can feed into Linrad.
73
Leif