• 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

Bugs in the gap

U

Unger

We have a 1kW AM with a bug problem. Insects crawl into the spark gap at the antenna base and fry themselves. With more power this might not be an issue but our little BE AM-1 throws a VSWR fault and blinks the power output a few times. If the bug is large enough it will knock us off the air until the dead bug is removed. Does anyone have any ideas for detering them? I do spray insecticide around the base but is washes away and/or dries up quite quickly.

Thanks for the help.
 
I think it would be amusing to put a bug zapper near the base, hear the bugs get zapped to the beat of whatever is playing ;D

Id try putting a powder/liquid combo around the base, and maybe a few of those bug traps.

Another idea could be to put a non conductible screen mesh around the base to prevent the bugs from getting in.
 
You may be able to wrap the gap in a non-metalic window screen material to keep the bugs away from the gap.
 
frankberry said:
You may be able to wrap the gap in a non-metalic window screen material to keep the bugs away from the gap.
Click to expand...

Do you think I would have an issue during heavy rain with arcing? Maybe I could try and see. i imagine i would have to remove before snow season when snow or ice could collect. That would be do-able.
 
I've not seen such thing. I have seen weeds and trees grow into the gap but have never seen a continuing problem with bugs. In many years with multiple stations, many including newer solid state transmitters this seems unique. I know the SX series had a tendency to blow output transistors on a whim. What kid of bugs I must ask?

Since this is in the midwest I might ask if Dennis is dumping bugs in the gap to see if you can find the problem? Are you finding residue or some indication bugs are the cause? Even if it were zapped I doubt enough moisture is there to have any residual problem unles this is an entire anthill or thousands of hornets.
 
For some reason knats are attracted to tower bases.
In the fall we get flying ants all over the tower. They're looking for a high launching point.
They also end up in the building when launching from the roof.
 
Do knats even in clouds cause the arcover to take place? Does a single arc keep the transmitter off? I didn't see a response from the poster but after the post my reference to Dennis Rund may be old as Dennis retired from WFIN last year. Their AM stations are WFIN Findlay Ohio and WCSI Columbus Indiana. I can't say that in Indiana I have ever had a bug problem, other than wasps in the feedhorn.
 
ChiefEngineer said:
other than wasps in the feedhorn.
Click to expand...
And I'm here to testify that they get very displeased when disturbed. Drive to dish, crack the window, spray the 25' wasp killer, roll up the window and pray.
 
This bug thing is WFIN Findlay. I looked and Dennis Rund retired a year ago. WOW.
 
ChiefEngineer said:
Do knats even in clouds cause the arcover to take place? Does a single arc keep the transmitter off? I didn't see a response from the poster but after the post my reference to Dennis Rund may be old as Dennis retired from WFIN last year. Their AM stations are WFIN Findlay Ohio and WCSI Columbus Indiana. I can't say that in Indiana I have ever had a bug problem, other than wasps in the feedhorn.
Click to expand...

Yes I am actually the person that was lucky enough to take the job when Dennis retired. He is a great engineer and even better person.

I know they are bugs because I see the bodies left behind with tiny legs left clinging to the ball gap. If a large enough bug comes along it will stick in the gap and get thouroughly toasted and the transmitter will fault and only come on in low power. Since my initial post I have spread liquid bug spray around the tower and on the base then added Sevin dust bug killer that is usually used on vegetble gardens. That combination seems to work rather well and has survived several rain showers.
 
I had to look up your location, then had to google Dennis and found him the Findlay publishing site. Good picture too. Congrats. I have a lot of background with the company being there in High School and beyond. One favorite story is from an old engineer who complained of a certain manager "If XXXX was on fire and I had a bucket of water I wouldn't cross the street to put him/her out."

I think the gap is too close then. I have seen gaps up to several inches apart. I have never set one in almost 40 years doing this so as with a spark plug, what is the standard? I have a nice looking picture here http://www.smeter.net/klo/antennas.php

Obviously the picture was at a time the owner knew someone would be taking a picture because I never see them like this. In my years of griping that people keep their sites clean I have one local TV site that makes me envious. WTHR 13 Indianapolis. used to live near there. Their site land looks better than a finely manicured golf course.
 
An old engineer once told me to gap my lightning balls about "1 credit card width per kilowatt in the tower." Been doing that for a few years now, so this 68 year old engineer will pass that on to you. Not to scientific but it's a good ball park and I've had extremey few lightning failures in the last 45+ years. None I could directly attribute to the tower, usually from the power lines.
 
bilco said:
An old engineer once told me to gap my lightning balls about "1 credit card width per kilowatt in the tower." Been doing that for a few years now, so this 68 year old engineer will pass that on to you. Not to scientific but it's a good ball park and I've had extremey few lightning failures in the last 45+ years. None I could directly attribute to the tower, usually from the power lines.
Click to expand...

Credit Card width or thickness?
 
Thicknes, and I don't think it's all that critical. Looking at several cards, thereis a slight difference in thickness, but doubt it's enough to matter. Bottom line, I've done it that way for a lot of years and not had problems with lightning at that point.
 
Thanks for the credit card info. We run 1 kilowatt during daylight hours so I think we might be a little wide right now if anything else.

Thanks for the help!
 
Do your adjusting on a humid day and ease that transmitter up while someone is watching out there. Tower impedance plays a roll in all of this. As the impedance goes up, so does the RF voltage, which is what makes things jump, of course. E = (I squared)x R
 
Try a cottage cheese plastic container (or similar) full of mothballs under the ball gap. They'll tend to evaporate over time, so you'll have to renew them periodically. Poke holes in the bottom so that rainwater can escape. I agree that increasing the gap should help.

We have problems with red-tail hawks, a couple who have lived on our towers for years. They love the view - helps 'em pick out dinner. I can tell when the tower field needs mowed when the hawks move down to the third set of guys because it's harder for them to spy victims.

I've had them poop rodent and bird fragments into the ball gaps, and that DOES dump the BE transmitter. Fun to clean up, too.... ::)
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom