X-50 versus X-200, X300, jt Diamond andtennid

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X-50 versus X-200, X300, jt Diamond andtennid

PostitusPostitas Ralfwind » N Mär 10, 2011 2:44 pm

Mõõtke ära kuidas on SWR nendel antennidel. 2 m ja 70 cm alas ja hakkame võrdlema.
Diamond antennidel on valdavalt ülipositiivsed kommentaarid aga üks vend teki katse:
I purchased the NA version with the N connector, recently from a local HAM who had one new in the package. He was going to use it for a project, but sometime later the project did not happen, so he sold it to me for a good price. I had planned on replacing the old quarter wave vertical that I had been using for my APRS I-Gate with this antenna.

Unfortunately this “no tune” antenna is garbage on the lower half of two meters. Below 146.0Mhz, the reflected power climbs dramatically. When I saw this on the SWR meter, I setup the analyzer and sure enough, the resonant point is around 149.5Mhz . Usable bandwidth is about 146.0 to 154.0 .
I guess that I would be all set if I was using MURS...

UHF is fine, nearly 10Mhz wide. The antenna was tested at ~17 feet AGL. I am glad that I tested it before it went up higher, but still it is disappointing that RF parts cannot get their QC right.

Thinking back, this is not the first time that I have seen this happen with an X-50.
A few years back our local EMCOMM group bought three of these antennas brand new as replacements for older antennas. One was to replace the antenna for our APRS digipeater.
So there I was, strapped into the tower, I had just tightened the new X-50 into place, when something told me to yell back down that the guys below should test it, while I was still up there (yes I shimmied down a few feet before they PTT). You guessed it, SWR over 2:1 . So we lowered that one back down and hoisted another up, and this time it was good. I sealed everything up, and that antenna is still in service.
After I came down from the tower, we tested the third X-50, and that one also would not have been a good match on APRS, although it was better than the first antenna that we tried. So the lesson learned was that each one of those X-50 antennas had a very different resonant point on VHF. I should have remembered that recently when I purchased that antenna from the local HAM.

He purchased the antenna from AES, of course they will not take the antenna back once it has been out of the door for more than three months, so I am stuck with this lemon.

Roughly half of the Diamond / RF Parts equipment that I have purchased in the last 19 years or so, has been garbage. I have tried in the past to deal with RF Parts on replacements, but they have always managed to screw me.

The moral of the story is never buy Diamond used, or shipped. Only purchase their products locally and test them right away, so that you can return them locally if needed.


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Re: X-50 versus X-200, X300, jt Diamond andtennid

PostitusPostitas postikana » N Mär 10, 2011 3:54 pm

Mina enda X50ga rahul ei old. Tundub, et nad on suht suvaliselt hääles. NR770 toimis sama hästi või kohati isegi paremini.
Minu eksemplar nägi seest välja selline.
http://test.kose.ee/cb/X50.jpg

es8bfu
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Re: X-50 versus X-200, X300, jt Diamond andtennid

PostitusPostitas es8bfu » N Mär 10, 2011 4:54 pm

Minul pole küll Diamondi antenni aga on UV300 mis on diamondi omaga üsna sarnane.. Analüüsisin miniVNA ga minimaalset SWR 2m lainealas ja tulemus selline:
Pilt

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Re: X-50 versus X-200, X300, jt Diamond andtennid

PostitusPostitas officer » N Mär 10, 2011 5:39 pm

...mul kasutuses V-2000:

145.500 = alla 1,1
433,500 = alla 1,1
50,200 = alla 1,4
ES2JT/304JT

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Re: X-50 versus X-200, X300, jt Diamond andtennid

PostitusPostitas hanno » R Mär 11, 2011 9:48 am

Minul on baasantenniks kasutusel X-300N. Pilt

144,500 MHz on swr 1,0 (osuti ei liigutagi ennast)
433,500 MHz on swr 1,1

Põlva pmr papagoi antenni mängib X-30N. Nii huvi pärast võin millalgi selle antenni ka ära mõõta.
HAM: ES6ACY; CB: 304HT

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Re: X-50 versus X-200, X300, jt Diamond andtennid

PostitusPostitas Mihka » K Mär 16, 2011 11:58 pm

Ka minu V-2000 on Officeri andmetega identne..seega ei saa midagi halba öelda...
Yaesu FT-8900R, FT-7800E,Baasantenn triband 6m/2m/70cm V-2000(ES5LCN)

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Re: X-50 versus X-200, X300, jt Diamond andtennid

PostitusPostitas Kaljukits » N Mär 17, 2011 10:44 am

Mul on kasutuses UV-200, X-200 ja X-300 -ei saa küll neile midagi ette heita.
73! de ES1TL, ES2TL, 3Ø4TL

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Re: X-50 versus X-200, X300, jt Diamond andtennid

PostitusPostitas ermo » N Mär 17, 2011 10:45 am

Mul katusel X200 ja maal X30.

X200

144-146MHz SWR alla 1.3
432-435 MHz SWR alla 1.2, kõrgemal sagedusel pisut tõuseb

X30

144-146MHz SWR 1.4 ringis
432-435MHz SWR 1.1 - 1.3

Üldiselt diamondi seeria antennid on väga heade
parameetritega. Samas, turul liikumas ka järgitehtud
isendeid ning neil pidid parameetrid olema kuis juhtub.
Yaesu FT-757, Icom IC-2350, HYT-TC518, Alan CT145...
Yagid 7el 2m + 15el 70cm
Vert X200
LOC KO38JJ

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Re: X-50 versus X-200, X300, jt Diamond andtennid

PostitusPostitas officer » N Mär 17, 2011 11:01 am

...ja ei tasu unustada, et üldjuhul mõõdame ikkagi mitte ainult antenni, vaid komplekti connector+kaabel+connector+antenn :roll:
ES2JT/304JT


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