[Moon-net] Activity report 8-9 sept. de SM5LE

Mon Sep 10 10:02:04 CDT 2007

Hi Ed,
sri, you compiled up a statement which I did not write down.
I just use the double for simplicity and I compared it with my and actualy
common opinion of our mini OK1KIR EME crew, being active almost 30 yrs
on EME.
The reasonable dish size clearly depends on the antenna gains and EIRP
watts of the others involved in the same hamradio job. That is the point
to relate things to.
I am in fact limited by the RX or better by the overall system noise
threshold which I require to be able copy an incoming CW (SSB) or JT65
or another signal.
Having a state-of-the-art NF, I can just change the antenna gain, i.e.
size of the dish (not more than to 0.5deg beamwidth) and G/CS figure
by forming the pattern shape.
That's all, but the exceptional personal skill of some or many experienced
ops (or PC SW) can decrease the "actual" NF down to few tens of dB,
hi !
On TX size I can change just TX power (license limitation !) and once
more increase the dish size up to the 0.5deg beamwidth. That's all as
well, no chance for op skill !
Consequently if I would not be limited by TX pwr, we could theoretically
all move TX power to kW levels and work much more stations even with
2m or smaller dishes.
So, the current recommendation for minimum size of about 3m dish or equivalent
relates to existing scale of rig parameters (do not forget license limits)
throughout the world 23cm EME community perceived as a minimum to get
at least somehow satisfied with all the effort spent on to get operational.
That's my sense about.
73,
Vladimir
OK1DAK/OK1KIR EME

----- PŮVODNÍ ZPRÁVA -----
Od: "Edward Cole" <kl7uw at acsalaska.net>
Komu: vladimir.masek at volny.cz, "SM5LE" <sm5le at telia.com>
Předmět: Re: [Moon-net] Activity report 8-9 sept. de SM5LE
Datum: 10.9.2007 - 16:35:33

> Vlad,
> 
> I'm not yet QRV for 23cm but find your remarks 
> interesting.  They would imply that the minimum 
> dish size to work a similar dish is 4m?  This 
> surprises me as I always heard (thought) that 3m was
> the minimum for 23cm+
> 
> I'm glad that I chose to keep the 4.9m dish vs. 
> the 2.4m for use on 23cm.  I have both.  It is my 
> plan that the 4.9m will see use on 23 - 9cm and 
> the 2.4m dish be used for 6 & 3 cm.  (I have 
> equipment for 23, 9 and 3cm for eme...other bands come
> much later)
> 
> I will not get the 4.9m dish installed this year 
> (unfortunately not enough time/money).  Summer 
> was consumed in building a small barn/shed and I 
> will be lucky to get some of my ham antenna 
> projects done before winter (6-weeks from now).
> 
> 73 Ed - KL7UW
> QRV 144 eme
> 
> At 03:40 AM 9/10/2007, vladimir.masek at volny.cz wrote:
> >Hi Sven,
> >do not be so sad. You can share experience e.g. with
> >LA9NEA and others
> >>with 2 to 3 meters.
> >If you take into account the fact that 2.2m dish vs
> >4.4m is a double^2,
> >>you would need to have 4x more rf pwr to get signal
> >comparable with
> >>their echoes !
> >Be sure that the others with such bigger dishes would
> >take much more
> >>attention about you when having 1 kW !! On the other
> >side, it is not
> >>as easy to create such heat, hi.
> >So, you have to accept only bigger guns with 6m and
> >over to be your favorites
> >>and the smaller would need a sked or think about higer
> >frequency (?).
> >>
> >That's life and our experience at OK1KIR (4.5m dish,
> >f/D=0.42 with very
> >>similar feed)confirmed that many times.
> >In others words it becomes very hard to break physical
> >axioms and nowadays
> >>really each one dB counts in and makes difference.
> >>We tried to breach physic on CW with Rex, VK7MO without
> >success. BTW,
> >>JT65C signals were great both sides, hi.
> >GL,
> >Vladimir
> >OK1DAK/OK1KIR EME crew
> >P.s.
> >FYI, we are getting your signal from M to O level
> >at maximum but were
> >>off for ARI contest.
> >
> >
> >
> >----- PÙVODNÍ ZPRÁVA -----
> >Od: "SM5LE" <sm5le at telia.com>
> >Komu: "MOON_NET" 
> ><moon-net at list-serv.davidv.net>, "Moobounce" <moon at moonbounce.info>
> >> >>Pøedmìt: [Moon-net] Activity report 8-9 sept. de
> >SM5LE
> >>Datum: 10.9.2007 - 12:26:20
> >
> > > "High degradation hits small dish" is the headline
> > > > > for this week end.
> > >
> > > Sutter day was reasonable with 5 QSO: s in 6 hours.
> > > > > BUT Sunday was very bad 1 QSO in 7 hours !
> > > Why is that so? Is one way propagation possible
> > > even
> > > > > with circular pol ?  (Something else than Faraday)
> > > > > or was it just that the high degradation, 1.8 dB,
> > > > > is significant for a 2.2 m dish ?
> > >
> > > 1st day worked: G4CCH, RW1AW, IW2FZR, OK1CA, DF3RU
> > > > > and F2TU.
> > >
> > > 2nd day worked: only ON7UN.
> > > Hrd and called like hel.. sorry , like very much
> > > was:
> > > > > SM4DHN, K1RQG, K9SLQ, K5JL and K5SO. (Do I hear
> > > to
> > > > > good for my 250 W @ feed?)
> > > Hrd in QSO: SV1OE and SP6JLW.
> > >
> > > The Sked with K0ALL was NIL. First sked time I
> > > was
> > > > > not QRV because I did not get any sked list. Was
> > > looking
> > > > > on Internet for K1RQG: s sked list but find only
> > > old
> > > > > ones. Now I have find out that I should ask for
> > > a
> > > > > "membership" on a mail list "Net Notes by K1RQG"
> > > (thanks
> > > > > info Howard).
> > >
> > > CU next time in low degradation and high declination
> > > > >
> > > /Sven SM5LE
> > >
> > > Ps What the difference between MOON_NET and Moonbounce
> > > > > mailing lists?
> > >
> > >
> > > -----------------------------------------------------------
> > > > > SM5LE in JO99bd
> > > 2.2 meter mesh dish F/D=0.34
> > > Septum feed OK1DFC. With choke ring.
> > > 250 W @ feed , CW ( 200W JT65 )
> > > Spid RAS rotator with MoonSked software by GM4JJJ
> > > > > Rig : TS-2000X (with 1296 MHz module).
> > > LNA : NE32684A cavity NF ~0.3 dB
> > > 8 dB sun-noise
> > > CW SSB JT65
> > > 1296 MHz only
> > > -----------------------------------------------------------
> > > > >
> > >
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