Getting back into it after a few years, problem

[brycexps]

Hi all,

After 3 or 4 years hiatus, I'm getting back into amateur radio. Unfortunately, over this time, I've become too incompetent to solve this problem.

With my Yaesu FT817, I'm running a 20 meter wire dipole combined with a ZM-2 tuner. For some reason, I'm only getting signal (clear conversations, etc) when the center conductor is in contact, when I screw the coax all the way in, outer shield in contact, everything goes to static. I remember using the setup just like this with no problems in the past. Hoping that someone can fill me in what I'm doing wrong.

Thanks in advance

Bryce N1BWH

 

[Engine104]

I'd start by checking the cable for continuity..

 

[WA0CBW]

Or a short!

 

[dlwtrunked]

Or a short!

Particularly at the other end of the cable.

 

[Lauri-CoyoteFrostbite]

I think you diagnosed your problem, Bryce, you just didn't recognize it. You have a coax short somewhere, probably along your feed line: mostly likely - if I were to put money on it- at the coax connector...... Use a multi meter to check it out for a short, as the others above have advised you. If it is shorted, cut it off , and re-test the cable. If it is the connector then clean it up and re-solder it back on to a fresh section of the cut back'd coax,-- or use a new PL-259. But it could be elsewhere along the line - maybe where the coax joins the antenna wires.
Regardless, I am 100% certain you will find a short.

Lauri

............and a PS....
if it was the connector and you are replacing it, -- before your re-solder anything, check to see that the shield is not sorting out etc. before- and after - you solder things back together. Solder carefully least you melt the inner coax dielectric into the outer portions of the connector-- and let it all cool completely before you do anything else.... that warm dielectric will be soft and can easily short out.

 

[RFI-EMI-GUY]

Could be open at the far end, in which case the outer shield is acting as antenna and capacitively coupled to the inner. In any case, time for an ohmmeter and prepair for a repair.

 

[prcguy]

I prefer my dielectric warmed, it's less crumbly that way and goes better with my afternoon cappuccino.

that warm dielectric will be soft and can easily short out.

 

[RFI-EMI-GUY]

I prefer my dielectric to be..

 

[wwhitby]

I don't have anything to add, but I want to welcome you back to the hobby!

I was out from 1998 to 2017. I kept my license, but wasn't active. However, after my then 14 year old son got his Technician ticket, I got back involved and got my General shortly after.

 

[Lauri-CoyoteFrostbite]

"..........that warm dielectric will be soft and can easily short out. "

Oh my, I had no idea ! ....did I type that ?...
Naw.... (laughs)

Good luck Bryce
Lauri

 

[ko6jw_2]

Are you feeding the dipole directly with coax? If so you might consider a 1:1 balun. That is after you fix the coax problem. I would also suggest that you could consider using the rear SO239 on the 817. Simple menu choice and reduces clutter on the front of the radio. While troubleshooting you might want to remove the tuner and check the SWR directly. Make sure that there is no problem with the tuner. A dummy load would be a good thing to have as well.

Best wishes for getting back on the air.