warships of JMSDF

[solid]

DDG 176 CHOKAI(KONGO class) and DD 101 MURASAME(MURASAME class)
http://61.132.72.44/dswc/upload/images/69005626601.jpg

DDH 142 HIEI(HARUNA class)
http://61.132.72.44/dswc/upload/images/69005626603.jpg

DDH 143 SHIRANE(SHIRANE class), DDG 171 HATAKAZE(HATAKAZE class), DD 153 YUGIRI and DD 154 AMAGIRI(ASAGIRI class)
http://61.132.72.44/dswc/upload/images/94186413821.jpg

LST 4001 Ohsumi
http://61.132.72.44/dswc/upload/images/57794667842.jpg

fleet review 2000 of JMSDF
http://61.132.72.44/dswc/upload/images/57794667841.jpg

DD 107 IKAZUCHI(MURASAME class), DD 152 YAMAGIRI, DD 153 YUGIRI and DD 155 HAMAGIRI(ASAGIRI class)
http://pic.tiexue.net/origin/2004_5/2004_5_13_71767.jpg

MURASAME class DD: DD 101 MURASAME, DD 102 HARUSAME, DD 103 YUDACHI, DD 104 KIRISAME, DD 105 INAZUMA, DD 106 SAMIDARE, DD 107 IKAZUCHI, DD 108 AKEBONO
http://pic.top81.com.cn/pic.aspx?id=22430

DDG 170 SAWAKAZE(TACHIKAZE class)
http://pic.top81.com.cn/pic.aspx?id=71776

 

[Revival_786]

Nice pics!

Why do warships have so many strings (see pics) :?

 

[solid]

Why do warships have so many strings (see pics) :?

I asked someone who is familiar with navy's equipments on the web.
He told me that there is a direct ratio between the antenna's length and
1/4 * wavelength. Those long strings are HF(High Frequency)-antenna.
High Frequency=long wavelength, so the HF-antenna is very long.
see this pic:

 

[Red aRRow]

Very nice pictures solid.

You are right about the antennas. The receiving antenna has to be about 1/4 of the wavelength.
However frequency is inversely proportional to wavelength. So the higher the frequency the shorter the wavelength. HF (High Frequency) is low compared with VHF (Very High Frequency), UHF (Ultra High Frequency) or SHF (Super High Frequency; used in Satcom<Satellite Communications>). Thus HF has comparatively bigger wavelengths than the other frequencies used for communications and thus slightly larger antennas.

 

[solid]

However frequency is inversely proportional to wavelength.

yeah, i made a mistake. V=frequency*wavelength, V is a constant (=velocity of light). almost have forgotten those highschool knowledge.

So the higher the frequency the shorter the wavelength. HF (High Frequency) is low compared with VHF (Very High Frequency), UHF (Ultra High Frequency) or SHF (Super High Frequency; used in Satcom<Satellite Communications>). Thus HF has comparatively bigger wavelengths than the other frequencies used for communications and thus slightly larger antennas.

:idea2 make sense of it. thanks for your detailed explanation.