• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

DAX-5 Xmtr - Anyone had Problems?

D

ddybas

Guest
I have a Harris DAX-5, running analog only. Can't get full positive modulation at 5KW output, works fine at 4KW. Harris Field Service has been very slow and hasn't come up with a solution. Just curious if anyone has had other problems with this box...I may be forced to replace it with a Nautel.
 
Are sure modulation monitor's 125% is accurate (including the carrier "zeroing" meter)? When was last time it was serviced?

For instance if you trying to get 135% modulation at 5 kW it ain't gonna happen.

PS Replacing a transmitter over this is foolish...
 
Yeah..it would be a dumb to get rid of the box without really being certain it was at fault....however, both the analog Belar AMM-3 and the digital Belar Wizard are showing pretty much the same poor performance...the Belar Wizard being only about 1 year old...I even have a 'scope on it, and it too shows that the positive peaks aren't as hitting +125 % at full power. I think I've checked it rather well. Unless there is some other way to check it...

BTW my BE AM-5 has no problems whatsoever giving me +125% unsing either of the mod monitors.
 
Use an O-scope. That way you'll know what the hell is really going on. As for Hair-Ass, their transmitters are acceptable, but your experience with them "being slow" has always been my experience also. Quite frankly, if your lucky, one of their monkey-asses will help read the manual WITH you. Only after having an owner/GM call them and raise hell did I get the one guy that had a clue when I had an issue the book readers couldn't solve. I'd stick with Nautel and Continental on your future purchases. You'll have better luck. I promise.

(BE isn't too bad either.. QC is just a bit sloppy on getting stuff from them new)
 
I hate to ask, but have you checked the common point impedance?
 
Well I haven't had -that- particular problem with my DAX (Yet). However mine is a DAX 6 running at 5400 Watts. Never tried it at full power.
I'm not a real fan of Harris stuff. Seems they always engineer it for the bare minimum. I guess you get what you pay for.
Stu
 
This DAX-5 came with the station when the station was bought so there wasn't much choice there. I've measured the "Z" at the feedline connector using an OIB right at the transmitter output, it's 50+j0.0 there so I'm not suspecting the antenna. The transmitter doesn't show any reflected power either. The problem occurs into a dummy load as well, so the problem lies inside the DAX-5 box.

I appreciate the suggestions and the help you've provided...I'll let you know what I uncover (if I ever do before I sell the thing).

Cheers.
 
I suggest you contact Maxwell Communications in Atlanta...their personell can quickly determine if it is a transmitter problem...I am a 50 year engineer myself, and they are my source when all else fails...a thought...
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom