Canadian TV, Computing and Home Theatre Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
20 Posts
Discussion Starter #1
This antenna looks like what possibly the Antennas Direct 91xg could be. This antenna is for ch 14-44. The dbd gain is 12.4 to 16.4 and if you want to figure dbi, it is around 14.4 to 18.4. I think the gain they are using is dbd. The width & height is close to the 91xg and the length is very close to a 91xg with an extension. I think the 91xg is just over 10ft with an extension and the LSL30 is just under 10ft. It is not 2 to 4 inches difference. This weighs 8lbs 3oz and i am guessing that is around the weight of the 91xg extended. It would be nice to find a dealer in Canada or USA selling these. The LS30 tracks along more like the 91xg. Here are some charts.

http://www.dnsip.ne.jp/~ryujakutsu/pwaizu/oldpwa/graphuhf.gif

http://www.dnsip.ne.jp/~ryujakutsu/pwaizu/oldpwa/graphu2.gif

http://www.maspro.co.jp/en/rev04/pagef/pdf_f/p11.pdf

http://www.geocities.co.jp/maspro_lsl30/

You can see the reflector and directors better in the next picture

http://www.geocities.jp/bfx2003/LSL30.html

It is many more pictures and an interesting antenna.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #2
Here is a vertical stack from the side

http://webpages.charter.net/rscarbro/verticalstack.jpg

Horizontal stack from the side

http://webpages.charter.net/rscarbro/horizontalstack.jpg

Quad stack

http://webpages.charter.net/rscarbro/lsl30_4_stack_at_shimizu_2.jpg

The gain chart of the LS20 and LS30 and on this one the LSL30 is not included. Notice how the gain is higher for the old band plan, like the 91xg on the LS20 and LS30

http://webpages.charter.net/rscarbro/ls20-1.jpg

This chart shows the LSL30.

http://webpages.charter.net/rscarbro/antenna copy.JPG
 

·
OTA Forum Moderator
Joined
·
24,867 Posts
Interesting stuff, but I've checked here, there, and everywhere in those pics and docs to find out what they measured, but did not see whether they are quoting:
  • dBd?
  • dBi?
  • net gain?
  • raw gain?
Beats me... on the conservative side I agree that it is probably in dBd but the other info would be great to know. That quad array, like all quads, would be a huge challenge to align and aim properly! :eek: For me the results of a head-to-head test with a 91XG would be needed before I'd order one.
 

·
Registered
Joined
·
7,360 Posts
This antenna is for ch 14-44. The dbd gain is 12.4 to 16.4 and if you want to figure dbi, it is around 14.4 to 18.4. I think the gain they are using is dbd.
My guess is that its dBi. The largest, the LS30, doesnt look like an 18+ dbi antenna to me.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #6
I emailed Maspro and did inquire if the antenna gain charts was done in dbi or dbd. The antenna box looks big to me and i do see some places shipping from Japan to North America but would they ship that antenna? Not sure. I also asked them if anyone in North America was selling the Maspro antennas. It looks like the LSL30 would run just over $100.00 in US dollars. Maybe they will email back soon.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #7
One more chart that is interesting, is the LS30TMH ch 14 to 30 antenna vs the LSL30 14-44 antenna. It seems that the Triax 100A's are 14-38 and i am not sure of the gain on them.

http://webpages.charter.net/rscarbro/gain.jpg

I may be wrong and it be dbi gain. It is interesting to see how the gain goes up in a smaller band width antenna like the LS30TMH or the Triax 100A's, comparred to a wide band antenna 14-69 or 14-44 or 14-51.
 

·
Registered
Joined
·
3,396 Posts
I entered Maspro's root website and (using Google's Toolbar Translator) clicked on "Site Map",
finally finding their SEARCH box. Searching on "LS20" & then "LS20 dbd" revealed fol. CORRECTED
pages, confirming Maspro is using dBd (referenced to a Dipole) rather than dBi = dBd + 2.15 db
in their "Love Story" antennas:

http://www.maspro.co.jp/web_catalog2010/images/manual/5046.pdf [In Japanese]
http://www.maspro.co.jp/web_catalog2010/images/manual/5032.pdf [In Japanese]
http://www.maspro.co.jp/new_prod/ls20tmh/ls20tmh.html [Google Translate to English]
LS20TMH, LS30TMH & LSL30 are optimized for the lower UHF channels, whereas LS20 & LS30 are Full-Band.
Note "Bimudaiporu" (phonetic Bi-Mode-Dipole) Driver Elements and "4-Stage" Directors....
And "high back and forth" must be the F/B Ratio, whilst "Half Angle" must be the Bandwidth.

Curiously, connections can be either 75-ohm Coax....or 200-ohm (NOT 300-ohm???) twin-lead....
Maspro doesn't even SELL 200-ohm twin-lead....only the standard 300-ohm variety.....

Additional Maspro Catalog pages (in Japanese):
http://www.maspro.co.jp/web_catalog2010/images/pdf/p001.pdf
http://www.maspro.co.jp/web_catalog2010/images/pdf/p012.pdf
http://www.maspro.co.jp/web_catalog2010/images/pdf/p018.pdf
http://www.maspro.co.jp/web_catalog2010/images/pdf/p019.pdf

Note last two pdf's illustrate UHF channels numbers for Japan vs North America vs Europe.
Japan UHF channels numbers are ONE LESS than North America (and Europe starts on Ch21)
(Japan Ch13 & Euro Ch21 is our Ch14):
http://en.wikipedia.org/wiki/Television_channel_frequencies
Here are North America vs Japan (very different) VHF channel charts (et. al.):
http://upload.wikimedia.org/wikipedia/en/c/cc/VHF_Usage.svg

PS: Japanese technical jargon is mostly in ENGRISH-A-RU, using KATAKANA phonetic characters:
http://en.wikipedia.org/wiki/Katakana
Each Katana character represents a phonetic SOUND, like Ka, Ku & Ko or a stand-along vowel
(first line in the above referenced table). Since Japanese doesn't use stand alone consonants,
the END of each word must contain a vowel. So "hard boiled egg" become "Ha-Do Bo-E-Du E-Gu"
and "Dipole" becomes "Dai-Po-Ru". [Since it doesn't exist in Japanese, "L" becomes "R".]
Having spent many months in Japan (early 70's), I learned KATAKANA (and HIRAGANA script form)
in order to read Hi-Fi equipment spec sheets....and some menus.....and don't ask for Fried E-Gu's.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #9
Thanks holl_ands for the good information on the antennas. Maspro did email back saying the antenna charts are in fact dbd and not dbi. It is no distributor in Canada or USA for the Maspro antennas. Looking at some of the shipping boxes of the LSL30 and LS30, they look long and big. I figure shipping would be expensive. The LS30TMH from ch 14 thru the lower 30's has nice gain along with the LSL30(14-low 40's).
 
1 - 9 of 9 Posts
Top