x50 Antenna vs half wave dipole

[Werthers]

x50 antenna vs half wave dipole.

Is there a huge difference?

People keep giving me conflicting information on it. Some people tell me... get an X 50 antenna you'll see the world of difference then others say... a half wave dipole will have the same performance as an X 50 antenna on 2 meters and will work on 70cms as a full wave. Sure enough the 2 meter half wave dipole works on both bands.

So it there a huge difference between the two?

[bigpimp347]

what do you call a half wave ??
if center fed not sure how it works out as a full wave on 70cms.
most X30/50/200 type antennas are mostly designed for VHF with their third harmonic frequency being UHF,
the bigger the antenna (X510) the higher the gain the poorer the radiation pattern (it's true)

so what 'half wave' do you mean ?

[paulears]

I think he means a half-wave dipole, as in two elements about 19" each - which will work as a ¾ wave at UHF.

An X-30 dual band in practice will offer a little useful gain over the dipole when both are mounted vertically. at VHF around 2.5-2.8dB more gain. A little more at UHF, but in practice this gain is a tickle on the meter. What IS different is the take-off angle. Dipoles give the classic donut radiation pattern, so quite a bit goes upwards - there's good amounts of RF at 45 degrees to horizontal. The X-30 has less going upwards so what it produces goes in a sensible direction. The X-50 has a little more gain and again, lower radiation angle. If your house is on the top of a hill, so you look down on the surrounding area, the simple dipole could be a better choice. I sell quite a few antennas and most customers are very happy - but a few return the X-30 as not being better than their dipole. The one on my office is better than the dipole on the same mast - but geography seems to be very important.

[bigpimp347]

I think he means a half-wave dipole, as in two elements about 19" each - which will work as a ¾ wave at UHF.

center fed dipole. and yup 3/4 wave at UHF the most easiest antenna to build and use,
only issue i've found is mounting off set from a pole/mast the interaction,
i mounted mine around 1/8th away from the main mast as work great as a 2 element beam.
one of the main problems trying to mount a center fed.

i've always found X30/50 types quite poor and gain pretty much nil, a mono band unity gain antenna can be just as good.
all depends on the purpose in hand if just for local ham chit chat most gain the antenna has is usually lost in the poor quality connections and coax used, and switch boxes and the like.

so some times going all out on good feeder and plugs and suitable location can be better than all out gain.

[Werthers]

Yep I've also found the x30 x50 antennas to be on the poor side. I have been a bit disappointed with the performance of these antennas although they work ok but could perform much better. There the only 2/70 antennas you can find on popular sites along with the other types from that series like the x500, x200 etc. The halfwave dipole actually performed slightly better on 2 meters compared to the x50. It would seem like there is zero gain on two meters but do have some gain on 70cms although not a great deal, I'd probably estimate an x50 antenna having about 2 to 3 gain on 70 and zero on 2.

[Mudslinger]

I did a little experiment with making a 1/2 centre fed dipole for use on PMR446 and I coupled it to my yaesu FT-4.

Using a short 3m length of RG213 it actually performed worse than the small rubber duck that the radio came with.

I would hope than an X50 etc would work better...

[Werthers]

I did a little experiment with making a 1/2 centre fed dipole for use on PMR446 and I coupled it to my yaesu FT-4.

Using a short 3m length of RG213 it actually performed worse than the small rubber duck that the radio came with.

I would hope than an X50 etc would work better...

Try experimenting with different coax types. At 3 meters RG8 or even RG58 coax will do.

I know some people are going to disagree with me for saying this but was using RG213 on my 2/70 collinear and it did not perform very well but when I changed the coax to RG58 which is what I had laying about it worked much better. I know RG58 coax can be lossy but at short runs its fine. Mini8 is generally better at UHF for a quick throw together antenna. RG213 coax is best for longer runs but the RG213 coax that I got was from the auction site and may not have been the real deal I don't know but all I can say is that RG58 worked much better so did RG8.

The x series antennas can be hit and miss. Some people get excellent results and other get poor results although this can be based on many factors, different heights ASL, terrain etc. They are cheaply made and mass produced and some have been known to have faults but most work ok however the performance isn't the best.