Problem with a diamond antenna x510hdm x510 x510n vhf uhf


My diamond antenna x510 hdm (x510hdm), that was selected to handle my 160 watts amplifier, stopped working last week-end.

I suspected that a capacitor blew since it happened while I was transmitting. I ordered the “high power” diamond antenna so this wouldn’t happen. It happened. The swr where it happen would read at 1.3 1.4 swr normally. The antenna is rated to 330 watts and it’s probably PEP with 1.1 swr. If the swr raise the capacitors inside doesn’t handle enough voltages to get close to the 330 watts rated.

I contacted (call, message, call, message, email, call, message …) radioworld, where I got the antenna not long ago, and they couldn’t help me and asked that I deal with the diamond antenna north america distributor. After many calls and couple email I gave up on trying to get any return from them in a reasonable time. Diamond antenna america is a division of rf parts company and I’ve had a very bad experience dealing with them in the past (support to Canadian market).

I took my chance with diamond antenna Japan and got quick reply to my emails (couple hours delay) and they gave me confirmation of the value used in the x510hdm since it’s different than a x510n or x510.

They also told me some antenna would come with 1000v caps and others with 500v caps. I’m not sure which one I have but my “not exploded” capacitors where 3pf and 11pf. The missing value was in serie with the 11pf and they confirmed me it was a 12pf 1000v that should go there. I got the confirmation from them edited on a picture. I’m adding the picture directly here if can be of future help for someone else.

I will try to source the part locally and replace it, if I don’t post any follow up it’s because everything went well.

BTW did you know a X510 antenna is resonant in the 220mhz band ? I’m using mine as a triband antenna to reach 220 mhz repeater up to 30-50 miles without any problems.


73, VA2SM

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2 Responses to Problem with a diamond antenna x510hdm x510 x510n vhf uhf

  1. Albert says:

    Greetings, I have the same antenna (x510hdm) with the same capacitors at the bottom that needs to be replaced but I cannot find the values for each one. If you can please help me decipher the values for each ones and their replacements (3c, 12 J KCK and 11 J KCK), thank you.

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