Comparing a Diamond X300 2m/70cm antenna with my home-brew colinear...with the help of M0UHF

Hi there, here's how we roll at HARS...helping each other out...for example by conducting signal tests to compare antennas, set-ups, radios etc. Here M0UHF was interested (as was I) to compare the performance of the Diamond X300 with my home-brew colinear.
I hope you enjoy the video.
Thanks for watching.
Keep safe.
73s,

[@timg5tm941]

Interesting how just a doubling of power saw a couple of s points increase. Just shows how the textbook doesn’t always follow the real world examples. Nice vid 73

[@OxfordShortwaveLog]

Thank you very much Tim - and yes, practical doesn't always follow theory! 73s, Clint

[@timg5tm941]

@@mikesey1 no it’s 2 (5 to 20 is 1; 20-80 is another).

[@NToombes]

Interesting video, was great to follow your testing session.

[@OxfordShortwaveLog]

Thank you Neil! 73s, Clint

[@2metercrew389]

Very interesting video.. maybe next time the other station can set up a video camera so we can see your incoming signal on his radio.

[@OxfordShortwaveLog]

Good idea. Who are the 2Meter Crew by the way?! 73s, Clint

[@2metercrew389]

We are just a bunch of radio nuts that love mountain topping on VHF but we also spread over it to all the ham bands..

[@kitswithkaren5003]

When you were cutting out on transmit could you not see the meter on your rig jumping into the red?

[@OxfordShortwaveLog]

No, I had my eyes on the camera. 73s, Clint

[@miketison4449]

Hola,a ver si puede ayudarme tengo una discono d130 original con una tirada de cable de 65 metros ultraflex 7 ,,vivo cerca de la ciudad a unos 4 kilómetros busco una antena para recibir vhf y uhf y a poder ser aviación y pmr con mayor claridad e probado la x510 original y la tuve que cambiar por la discono de nuevo porque recibía algo mejor la discono, siendo las 2 nuevas y comprobado todo.Me gustaría cambiarla para algo mejor pero no lo tengo claro,si es por el cable que pierde demasiado al tener 65 metros muchas gracias

[@mrmrlee]

I believe the colinear has a bad connection somewhere. As others noted, you were cutting out during transmit, but only on the one antenna.

[@OxfordShortwaveLog]

Thanks for your comments. 73s

[@RICHLFCFAN]

Good videos bud. Did you ever find out why your signal was diviating to your buddy. I have a similar antenna and some ppl report my signal moves slightly up and down without wind blowing. Was it a lose connection with your coax plugs? Regards Rich

[@OxfordShortwaveLog]

Thanks Rich. No idea - could be the antenna moving in the wind - no - all connections sound. 73s

[@RICHLFCFAN]

@@OxfordShortwaveLog Thanx for the reply. I bought the Sqbm500p mark 2 from Moonraker. Not bad at all 😎

[@frankpa1vhf712]

I am interested in the reason why it cut out. If I hear it right, the receive also cut out on the homebrew. Did it overload on 50 W, was it a loose connection? Very interested.

[@Scif64]

You should really get the vhf/uhf antenna's above the apex of the roofs, i am sure you will be doing this in future.

[@OxfordShortwaveLog]

Lol yes Steve when I have time. 73s, Clint

[@johndesmond9845]

Your 5w/10w results suggest that the X300 in its location is 3dB better than the home brew colinear in its location, not 9dB.

[@OxfordShortwaveLog]

There was one comparison on a particular TX power where the difference was 1.5 S units which is 9dB. 73s

[@johndesmond9845]

@@OxfordShortwaveLog The problem with that is that you are assuming that an S unit is 6dB which it may not be. When you are using different power levels, you are dealing with known quantities. Your signal report with 10w into the home brew colinear was S7. Your signal report with 5w into the X300 was s7. As the difference level is 3dB that that suggests a difference of 3dB between the home brew antenna and the X300 in their current locations. If you can get the X300 above the height of your house then you should see a big jump in signals as you get above the clutter.

[@dazr6604]

Well X300 is only 9dBi gain on 70cm and you're on 2m

[@adamivanecky3907]

the Diamond X300 antenna 6.5 on 2meters and on 70cm 9 dbi

[@OxfordShortwaveLog]

Yep! 73s