Re: Puyallup, WA Ultralight TP's for 9-19


wa8lcz
 

HI GARY,

If the relay shorted out the unused turns, in this case 4 turns, then the remaining 2 turns with the same var cap, is very efficient, at receiving the top end of the band. i copied a 1kw signal from NJ to MI at 1680kc. because of local noise and an indoor antenna, it took me a year to log WTTM. I've been using this setup on different loops for a year. my thinking is: use the smallest number of turns with a large var cap 1150pf, this cuts down on total wire resistance and losses. I see you use a small var cap 365pf and more turns. wonder which system is best ?

byron

--- In ultralightdx@..., D1028Gary@... wrote:

Hi Byron,

Thanks for your suggestion. Yes, I've done a few experiments by tapping
off some turns, and using switches both for reduced coil inductance, and for
adding capacitance to lower a loop's tuning frequency. I haven't yet run
A/B DX signal reception tests to determine how well these modified loops
stack up against the fully-symmetrical models, but there is a lot more
experimentation that could be done. Since the largest PVC loops are always outside,
everything must be waterproofed, and made as secure as possible to
withstand heavy wind.

After my initial experimentation to develop the large-size (6' sided and
larger) PVC Loops in the spring of last year, most of the additional work
has been to develop practical portable PVC Loops, which can be quickly
disassembled to fit inside a compact car trunk for DXpeditions. There is a world
of additional experimentation that could be done with these cheap and
effective antennas, which I personally believe hold the greatest potential for
making Ultralight radios very competitive with table receivers in all-out
DXing (at least here on the west coast :-).

73, Gary DeBock (in Puyallup, WA)




In a message dated 9/20/2010 5:30:03 A.M. Pacific Daylight Time,
wa8lcz@... writes:




hi gary,

have you tried tapping off a few turns on your 9 ft loop for the higher
freqs (1000 to 1700 kc)? I use 2 turns for hi freqs and 6 turns for low freqs
(530-1000 kc) on my 34 inch loop and it works pretty well, across the
entire band. you could use a relay to select 2 or 6 turns.

byron

--- In _ultralightdx@... (mailto:ultralightdx@...)
, D1028Gary@ wrote:

Hi Kevin,

Thanks for your comments on the TP-DX reports, and of course I knew that
these that these monster loops would be strictly outdoor animals in
rainy
western Washington, so they were designed with some serious weather
protection.

Like I was telling Bruce on the IRCA list, even Guy Atkins (4 miles away
to
the SE, in Puyallup) and I have major differences in our TP-DXing
results,
with Guy pulling in far more high-band TP's and me pulling in more
low-band TP's. Part of this may be related to our soil differences (he's
on a
rocky hill, while I'm in a fertile river valley), but the main reason
may be
our completely different antenna systems. The 9' PVC Loop (like all
tuned
passive loops) has its highest "Q" and best performance on the lower
tuned
frequencies, and its combination of very high gain and single-frequency
optimization can be fairly potent from 530 kHz up to about 900 kHz. In
comparison
to single-loop directional antennas (like those used by Guy and Bruce),
the 9' PVC loop loses this relative advantage when tuning the higher AM
frequencies, and both of these DXers can routinely receive high-band TP
audio
that doesn't show up here. So it's essentially a bizarre situation where
the
9' PVC loop seems to be an overachiever on the lower AM frequencies, and
an underachiever (relative to Flags, Pennants, K9AY's, etc.) on the
higher
AM frequencies. Guy and I have known about the strange differences in
our
TP-DXing results for some time, and plan some additional tests on this
fascinating subject as rare free time allows.

73, Gary

In a message dated 9/19/2010 4:31:43 P.M. Pacific Daylight Time,
satya@ writes:




Another impressive list, Gary! I hope you don't get too wet standing
under your skyscraper loop every morning - maybe take a couple more
pieces
of PVC and put an awning on it :-)

I second what Brice P. said earlier - what a difference 40 miles makes,
as
your list is quite different from mine in some regards. 837-China was in
good here as it was with Bruce, and 693 was easily the best of the JJ big
guns here. 1287-JJ was pretty good at times as well. I heard two
stations on 657, judging by the dueling hets, but again 660-KAPS foiled
any plans to hear them; I have reversed the direction of my super loop to
have a northward null, so perhaps things will be easier tomorrow.
1566-HLAZ was good all morning, but 1575 was but a light het.

Kevin S
Bainbridge Island, WA

Hello All,

It was another China morning here, with moderate signals showing up on
various new frequencies like 684 and 1044 kHz. There were no dramatic
fade-ins
(like yesterday's 657-China) and signals in general were not at
yesterday's
strong levels, but the morning was another indication of shifting
propagation bringing more Chinese areas into play. The Japanese and
Korean stations
> seemed a little down in strength compared to previous days, though,
and
"big gun" TP audio didn't sound very big this morning.

Rare decent audio on 684 kHz was observed here for the first time this
season around 1330 (apparent Chinese), and CRI on 1044 kHz had its best
signal
of the season so far with its Japanese language program around 1335.
The
> CNR1 stations on 639 and 756 had their best audio so far, and 927 and
936
kHz took turns producing fair audio. In comparison to these, audio from
the
other typically strong Asians on 603, 648, 657, 666, 675 and 738 was
off
in
strength a little, and the NHK stations weren't especially vibrant.
> One interesting find around 1325 was a strong, ragged carrier on 702
kHz
(a
frequency with severe 710-Seattle splatter here), which sounded like a
typical (rickety) North Korean transmitter. No TP has ever been logged
on
702
(or 711) here because of the oppressive KIRO splatter, but the 702 kHz
> signal disappeared right after the huge 9' loop was wrestled around in
an
optimistic attempt to null KIRO (easier said than done :-) It's great
to
have
Walt's TP reports back from Masset-- a location in a completely
different
Asiatic propagation league than Puyallup!

The following were received on a C.Crane SWP Slider model (7.5"
loopstick)
inductively coupled to a 9' sided PVC tuned passive loop in the back
yard:

594 JOAK Tokyo, Japan Fair-good with Japanese conversation around 1312
603 TP-Mix UnID Chinese station having the edge over HLSA Korean at
1308
639 CNR1 (Many stations in China) Fair-good Chinese speech and music,
1338
648 VOR Razdolnoye, Russia Chinese program at fair strength w/ fades,
1321
657 Pyongyang BS, N. Korea All alone this morning but usually at fair
strength
666 JOBK Osaka, Japan In and out with Japanese speech at anemic
strength
675 VOV Hanoi, Vietnam Fair Vietnamese signals in 680 splatter, 1318
684 UnID Fair Chinese speech fading in suddenly around 1337; first
Asian
audio
heard on this frequency since last season, but no ID clues
702 UnID Strong ragged carrier presumed from NK, but too much KIRO
splatter
at 1325 to dig out the funky audio
738 BEL2 Penghu, Taiwan Fair Chinese speech over a presumed HKLG in
this typical September mix
747 JOIB Sapporo, Japan Fair-good signals no match for KXL splatter at
1323
756 CNR1 China Fair-good Chinese program at 1335, best sigs of season
so
> far
774 JOUB Akita, Japan NHK2 program barely audible in severe KTTH slop,
1311
783 UnID Threshold audio (apparently Chinese) showing up on this
frequency
891 TP-Mix An anonymous collection of weak TP stations drowning each
> other out
927 China (presumed) Weak to fair Chinese program fading in and out
repeatedly
936 China (presumed) Slightly stronger than 927 with Chinese speech at
1318
> 972 HLCA Dangjin, S. Korea Weaker than usual with Korean program at
1337
1035 China (presumed) Fair-good Chinese speech and music for most of
morning
1044 CRI Jiangsu, China Good signals (best of season) with Japanese
language
external program at 1335
1053 Korean Jammer Not as vibrant as usual this morning, but no TP
co-channels
1134 TP-Mix A typical snarl of JOQR and KBS at good strength around
1338
1377 China (presumed) In and out with poor to fair audio for most of
morning
1566 HLAZ Jeju, S. Korea Good strength with Japanese religious program
at 1306
1575 VOA Ban Rassom, Thailand Fair Asiatic language audio around 1302
1593 China (presumed) Threshold audio with deep fades for most of
morning

73 and Good DX,
Gary DeBock

>

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