This past Saturday, I went to the Columbus hamfest and ARRL Great Lakes Section Conference.  It was a disappointingly small hamfest for being on the NE side of the second-largest city in Ohio (full disclosure: that’s CITY population, regional population puts them third, behind both Cleveland and Cincinnati).  I think I spent one hour there and about $40, including admission.

On my way out, I stuck my 10m hamstick on the truck.  I knew there was a QSO party on 10, so I thought I’d jump on while driving.  I figured I’d check the antenna (which I’ve never tuned).  I set the rig to low power and CW and pushed the mic button.  SWR was great.

Fearing that such a good SWR for a never-tested antenna was too good to be true and not hearing a CW tone, I set the rig to AM on low power to check.  Same SWR reading.  So I set the power to 2 (out of 10) and checked again.  SWR through the roof.  I contemplated going back in to buy another hamstick to get the small Allen wrench to adjust the stick, but decided that spending more money without a full understanding of the issue (and wondering if the problem was tuning or common mode current), I figured I would have been putting good money after bad and decided to leave and just listen on 10 on my way home until I got in the area of the repeater.

When I returned  home (well, several hours after I returned home), I did a little bit of reading on the mobile HF oracle (k0bg’s website) and it confirmed my common mode suspicions.  Looks like I need to get an order in for some mix 31 ferrite beads.  I need to do some vehicle maintenance, so I may try to do all of it next weekend.

Additionally, I spoke with another local ham on the following Monday that gave me a few pointers courtesy of a friend with a 706, including to put a ferrite on the power leads and to make sure the bonding is done well – he had to strip paint to get a good bond.

So in the immortal words of K5PO from the Noise Blankers (who ironically has an Icom right in front of him and his name is eerily similar to mine)…
Put A Ferrite On It

-73-


Category: Equipment

About the Author

Andrew is the owner of this blog and enjoys computer programming, building things, and photography. He's a pretty busy guy, which explains why updates to this blog are so infrequent.

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