[Wswss] Holiday Update 11/21/12, was: 23CM35 report on Friday net 11/3/12 0300Z

[Courtney Duncan]

All my new LMR-600 / 400 is in place and I have a semi-permanent situation to test with for a while.  Looks like total loss between the rig and the antenna is 3.7 dB meaning I'm getting about 9 W out on the antenna for 20W in on the other end, and the receive system NF is around 4.5 dB (estimated).  (All based on Bird 43 - 50K slug measurements.)  This is about a half dB worse than it was with the Heliax (that AF6NA is inheriting) before it broke.  (About 6 dB better than after it broke.)

Dennis, yes, more oomph would help and I nearly impulse bought those 150W finals from W6PQL last week.  Although something like that fits into the architecture I already have, I stopped short when I realized I'd need a heat sink and, ultimately, a box, and some power switching and maybe another Bird slug (do they even make a 250K?) and other stuff before I was really cooking.  Doesn't mean I'm not gonna do it, just means that it's not on the short list for before Christmas, both from a time and $$ standpoint.  Definitely on the list, though, and in hot competition with my vow to also get on 10 GHz with you guys.

This morning I found the K6QPV DM12mq beacon at S-6 (-111 dBm!) and used the occasion to take some measurements.  Of course, signal levels from the source fluctuate by several dB over the several minutes it takes to make these measurements, so these are not precision measurements but they do confirm basic antenna performance, and, more importantly, indicate another way I can attempt to work some of you down in the basin.

http://www.m2inc.com/pdf_manuals/23CM35.pdf

Says the gain is > 20 dBi, 3 dB beamwidth around 18 deg., F/B around 25 dB.  None of my measurements disagree with that.  In particular I would say the 10 dB beamwidth is about 40 deg., the gain is at least an S-Unit better than I'm accustomed to, and the F/B is OTO 30 dB.

I'm comparing to the retired WA5VJB beam (being inherited by W6IEE) that the Handbook says could be 13.5 dBi and which has been fixed at about 135 true for the last year or more with the intent of being on K6TSK and that San Diego beacon.  On that antenna I've never seen the beacon more than S4.

HERE'S THE IMPORTANT THING FOR TODAY

I'm seeing the beacon peak at 144 true which agrees with geometry for DM04vf to DM12mq.  I'm also reading it at about the same signal level at 230 true, an obvious reflection off nearby mountains a couple of miles away.  This suggests a possible opportunity.

If you look at my horizon view

http://www.heywhatsthat.com/?view=ABSPUJ9E

You'll see that I'm actually blocked to the SE.  I'm seeing the beacon and Ralph and Dennis through a little notch in the hills there.  If I point to the SW (the hills that W6IEE resides behind) I reflect off something in the vicinity of Tongva Peak and get nearly as much signal from the SE as I do "direct."

Next Friday net I'll try Ralph on the reflection heading.  

In general, my horizons look hopeless to the high desert, although I do hear N6NB, DM05sb, 144.293 routinely, if weakly, on some path up the valley (about 300 true).  Still, reflection paths should be explored.  Other horizons are fair to poor everywhere except due south (Catalina, water, Antarctica....) but this reflection discovery brings new hope to SE headings, and other possible reflections.

So, in the spirit of Doug, K6JEY, who would like us all sitting on chat all the time in order to maximize our chance of opportunity QSOs, give me a call on 144.200 (also beamed to 230 true, could get a similar reflection, right?) and if I'm sitting here we can try something on 23 cm .  Or heck, barring that, call my cell, 818.825.9507 and I'll tell you I'm at Von's and won't be back in the shack for three hours.

For those of you targeting missiles, I'm at precisely DM04vf30jr

73 and QRV,

Courtney, n5bf/6, DM04vf30jr


On Nov 2, 2012, at 9:15 PM, Courtney Duncan wrote:

> I replaced a fixed pointed WA5VJB 8 element yagi with an M^2 23CM35 on a rotator this week.  Getting 7-8 watts into the antenna.  Preamp is in the shack so the system noise figure is worse than 5 dB.
> 
> On the Friday 1296.100 net at 0250Z, saw/heard Ralph, K6TSK, at 56, where 54 is normal.  He said I was loudest he'd ever heard me, and heard a carrier on my signal....  (That would be a DSP-10 issue.)
> 
> Armed with a list of likely call signs and beam headings from qrz.com, I heard some other stations.
> 
> 0254 heard Ralph check in W6DQ.  Beamed 143.  Absolutely nothing heard from W6DQ.  :-(
> 0256 heard Ralph probably saying "KI6FF, David" could barely hear the other station.  Didn't talk enough to peak up on him.  Would have been nearly the same beam heading. Might have been workable on CW.
> 0304 heard Ralph say "Larry"  Probably K6HLH.  Beamed 38, nothing heard.  (Nothing expected, mountains, would have to look for knife edge or a reflection.)
> 0312 heard Ralph say "W" at the end of a call.  W6QIW?  Heard peaks on the checking in station while rotating to 280.  Could have worked him on USB if I'd gotten there in time.
> 0314 heard Ralph calling N6ZE for a couple of minutes.  Beamed 269, heard nothing.
> 0327 heard Ralph telling somebody that DQ (EQ?) was going to 120 and QIW was going to try to work him on CW.  Heard Ralph say "Chuck."   Maybe EQ then.
> 0335 heard Ralph working "PI" N6PI?  Nothing heard from other end.
> 0334 heard airplane multipath on Ralph's CW.
> 
> 0337 QSY to 1296.120.
> Made blind CW calls to
>  W6QIW @ 280,
>  W6DQ @ 143,
>  N6EQ @ 077 (not expected through mountains),
>  N8DEZ @ 304, and
>  W6DQ @ 149.
> All NIL.
> 
> N8DEZ and KF6RNT didn't check in or I would have heard them.
> 
> When K6TSK NCS is beamed off me, copy is not Q5 anymore, and I would say that conditions were "moderate flutter."  There were Q5 copyable syllables followed by mush.  I'm used to this from 160 m. and SS type operation.  I'm hearing this same thing back on the K6QPV/B 208 km SE here right now.
> 
> The new beam works, looks it might double my number of stations workable might have doubled, and a new tag end of coax is on order (to arrive Monday) that should improve the overall cable run from rig to antenna from 4.5 dB to 2.5 dB loss.  Then we'll try again, but I may need a schedule or some VHF coordination and fooling around to actually work anybody but Ralph!
> 
> Courtney, n5bf/6 DM04vf
> 
> 
> "It's science. They don't know anything; they just make a lot of educated guesses."  -- Viannah Duncan
> 
> Courtney Duncan, n5bf/6
> cbduncan at earthlink dot net
> 1296.100, 1.810.
> n5bf at amsat dot org
> 
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"It's science. They don't know anything; they just make a lot of educated guesses."  -- Viannah Duncan

Courtney Duncan, n5bf/6
cbduncan at earthlink dot net
1296.100, 1.810.
n5bf at amsat dot org