Topics

Station weirdness


Jerry N9AVY
 

This morning I turned on rig (FT-1000MP) and hit the antenna turner button to make sure antenna was working. It shut down antenna tuner and said "high SWR" . Tried other antennas and had same results. Turned off rig for a couple hours and everything was okay and worked fine. Can't help but wonder if this might be moisture related or some external to antennas.

It's a puzzlement ...

Jerry n9avy


Rick - N7WE
 

Jerry-
I had something similar happen last week.  Sudden hi SWR on all bands.  Grabbed the MFJ 259B and started working backwards from the vertical.  That was about 9 AM and the heat index was already near 100.  The antenna checked OK.  Jumper to the bulkhead fitting checked OK.  Fitting itself checked OK.  But when I got to the main coax on the other side of the bulkhead fitting, the waterproofing was split and the PL259 wasn't even finger tight.  Now the waterproofing was 2 layers of self-bonding silicone tape covered with a double wrap of 3M Scotch33.  It had simply split - from the heat, humidity, and UV I guess.  First time I've seen that in many years of using that waterproofing technique.  And that wrap as new about 20 months ago.  After it split, I guess the PL259 just worked loose from expansion/contraction in our lovely summer.  Tightened it back, rewrapped with 2 layers of silicone tape, 2 layers of 3M Scotch33, and everything is back in normal range.  Took about 2 hours with several water and "go inside and cool down" breaks.  Someone once told me that 95% of all electronic faults are in connections!  In my instance they were right.  Good luck and hope you find your problem and fix it easily.
--
Rick - N7WE
070 - #1602


Jerry N9AVY
 

Rick:

Turned everything off for a couple hours and then all was okay again. Probably need to check coax connectors as you suggested. All affected antennas are on tower and fed into a remote switch on tower. Everything goes outside on single hunk of coax.

Not able to climb tower so can't check things up there. Have always suspected the balun on Force 12 C3 being a ceramic may have a moisture absorbing crack somewhere. Tower climbers now are too expensive ... all my usual guys retired from climbing.

Have noticed that when noise level in early morning in NIL that's when I may have problems.

I'll keep watching things and hope they go away, but that's wishful thinking.

Jerry N9AVY

On Wednesday, August 5, 2020, 04:09:33 PM CDT, Rick - N7WE <n7we1980@...> wrote:


Jerry-

I had something similar happen last week.  Sudden hi SWR on all bands.  Grabbed the MFJ 259B and started working backwards from the vertical.  That was about 9 AM and the heat index was already near 100.  The antenna checked OK.  Jumper to the bulkhead fitting checked OK.  Fitting itself checked OK.  But when I got to the main coax on the other side of the bulkhead fitting, the waterproofing was split and the PL259 wasn't even finger tight.  Now the waterproofing was 2 layers of self-bonding silicone tape covered with a double wrap of 3M Scotch33.  It had simply split - from the heat, humidity, and UV I guess.  First time I've seen that in many years of using that waterproofing technique.  And that wrap as new about 20 months ago.  After it split, I guess the PL259 just worked loose from expansion/contraction in our lovely summer.  Tightened it back, rewrapped with 2 layers of silicone tape, 2 layers of 3M Scotch33, and everything is back in normal range.  Took about 2 hours with several water and "go inside and cool down" breaks.  Someone once told me that 95% of all electronic faults are in connections!  In my instance they were right.  Good luck and hope you find your problem and fix it easily.
--
Rick - N7WE
070 - #1602


 

Jerry,

I had a similar problem but limited to my vertical.  High SWR but an hour later tuned perfectly.  Two or three days later high SWR again.  Turned out to be a dirty connector at the antenna.  One shot of Deoxit and still working fine six months later.  Like Rick said 95% of the time it's a connector so might want to check them all out.

John
KC3FL


Ron Bosch
 

Rick and Jerry,
" Good luck and hope you find your problem and fix it easily."
Any insight on how to make those two go together would be greatly appreciated :-)  I seem to do well on the first, but miserably on the second!!  Glad to see that I am not the only one who has the weird and strange happen to them, although most of mine as a newby, seem to be self-inflicted right now :-).  Latest learnings:
1.  When you tune a 10M dipole on 80M it is really hard to get much signal out :-)
2.  An MFJ-939I is an amazing autotuner that I am pretty sure could tune my truck's satellite stub to 80M!
3.  Label your antenna switches!

The mystery right now is that I seem to have problem with my 132' end fed zepp on 40M, I can tune it flat, and the match shows good, but when I get above about 35 watts out, it starts tripping the self-protection on the IC-7100 and reducing power, but not to a regular level like it would if it were a steady high SWR, it kinda jumps, lowers power SWR goes down, radio kicks power-up, and the cycle begins again.  It tunes fine and I can get 100 watts to the tuner in on every other band, so I suspect I am getting some weird resonance bridge as I increase power, but it is definitely power dependant, since at about 35 watts it goes away completely.
My first kick at the cat is I plan to extend the end fed to 202.5 feet, which I think I can do in the space I have.  The other monkey in the wrench is that is is only about 10 feet high because the Neighbourhood Nazi's would crucify me if they knew I was operating an HF station here.  I already tried changing the length of the counterpoise, with no discernable effect.

Ron
KE4DRF
 
Judging by personal experience, the next public health crisis after COVID 19 is likely to be cirrhosis.
Ron Bosch

"..any man who may be asked what he did .. to make his life worthwhile, I think can respond with a good deal of pride and satisfaction" 'I served in the United States Navy."
John F. Kennedy

When I was young and bold and strong,
Oh, right was right, and wrong was wrong!
My plume on high, my flag unfurled,
I rode away to right the world.
‘Come out, you dogs, and fight!’ said I,
And wept there was but once to die.
But I am old; and good and bad
Are woven in a crazy plaid.
Dorothy Parker

"The best lack all conviction, while the worst are full of passionate intensity"
Wm Butler Yeats

"Believing with you that religion is a matter which lies solely between man and his God, that he owes account to none other for his faith or his worship, that the legislative powers of government reach actions only, and not opinions, I contemplate with sovereign reverence that act of the whole American people which declared that their legislature should "make no law respecting an establishment of religion, or prohibiting the free exercise thereof", thus building a wall of separation between church and State."
Thomas Jefferson


 "Fix reason firmly in her seat, and call to her tribunal every fact, every opinion. Question with boldness even the existence of a god; because, if there be one, he must more approve the homage of reason, than that of blindfolded fear."
Thomas Jefferson in a letter to Peter Carr


A Government founded upon justice, and recognizing the equal rights of all men; claiming no higher authority for existence, or sanction for its laws, than nature, reason, and the regularly ascertained will of the people; steadily refusing to put its sword and purse in the service of any religious creed or family, is a standing offense to most of the Governments of the world, and to some narrow and bigoted people among ourselves.
Frederick Douglass






On Wed, Aug 5, 2020 at 4:09 PM Rick - N7WE <n7we1980@...> wrote:
Jerry-
I had something similar happen last week.  Sudden hi SWR on all bands.  Grabbed the MFJ 259B and started working backwards from the vertical.  That was about 9 AM and the heat index was already near 100.  The antenna checked OK.  Jumper to the bulkhead fitting checked OK.  Fitting itself checked OK.  But when I got to the main coax on the other side of the bulkhead fitting, the waterproofing was split and the PL259 wasn't even finger tight.  Now the waterproofing was 2 layers of self-bonding silicone tape covered with a double wrap of 3M Scotch33.  It had simply split - from the heat, humidity, and UV I guess.  First time I've seen that in many years of using that waterproofing technique.  And that wrap as new about 20 months ago.  After it split, I guess the PL259 just worked loose from expansion/contraction in our lovely summer.  Tightened it back, rewrapped with 2 layers of silicone tape, 2 layers of 3M Scotch33, and everything is back in normal range.  Took about 2 hours with several water and "go inside and cool down" breaks.  Someone once told me that 95% of all electronic faults are in connections!  In my instance they were right.  Good luck and hope you find your problem and fix it easily.
--
Rick - N7WE
070 - #1602


Jerry N9AVY
 

Can't climb tower - doctor's orders.

About every year or so I disassemble tower mounted remove coax switch (it's down low) and burnish the open frame relay contacts. Ameritron 5-position. Only problem I ever had with switch was when a spring broke on armature and I repaired it ... something I used to do many years ago on the job.

Jerry n9avy

On Wednesday, August 5, 2020, 04:58:24 PM CDT, John - KC3FL via groups.io <kc3fl@...> wrote:


Jerry,

I had a similar problem but limited to my vertical.  High SWR but an hour later tuned perfectly.  Two or three days later high SWR again.  Turned out to be a dirty connector at the antenna.  One shot of Deoxit and still working fine six months later.  Like Rick said 95% of the time it's a connector so might want to check them all out.

John
KC3FL


 

Ron,

Usually when a zepp won't tune on one band the problem is that your ladder line is at a bad length.  Try adding or removing a few feet of the ladder line and see if that fixes it.

John
KC3FL


Rick - N7WE
 

Ron-
I'd suspect common mode RFI.  Lots of info available.  Google "common mode rfi on end fed antenna".  If I'm right, a properly placed choke should fix it.  Good luck.
--
Rick - N7WE
070 - #1602


Ron Bosch
 

Rick and John,
Thanks for the ideas.  I am running the zepp with coax to the 1:49 I built, although I am going to change to a Palomar UNUN because the one I built is not standing up to the humidity in Houston.  The common line current makes sense to me, since I have a very good ground system, and that would explain why I don't see the other effects of common mode RFI.  One question I have is should I place the choke on the antenna side of the lightning arrestors ( all my coax runs go to a set of lightning arrestors tied to my ground rod, and then each one runs into the house and to my antenna switches), or should I put the choke on the radio side of the lightning arrestor?

Ron

Judging by personal experience, the next public health crisis after COVID 19 is likely to be cirrhosis.
Ron Bosch

"..any man who may be asked what he did .. to make his life worthwhile, I think can respond with a good deal of pride and satisfaction" 'I served in the United States Navy."
John F. Kennedy

When I was young and bold and strong,
Oh, right was right, and wrong was wrong!
My plume on high, my flag unfurled,
I rode away to right the world.
‘Come out, you dogs, and fight!’ said I,
And wept there was but once to die.
But I am old; and good and bad
Are woven in a crazy plaid.
Dorothy Parker

"The best lack all conviction, while the worst are full of passionate intensity"
Wm Butler Yeats

"Believing with you that religion is a matter which lies solely between man and his God, that he owes account to none other for his faith or his worship, that the legislative powers of government reach actions only, and not opinions, I contemplate with sovereign reverence that act of the whole American people which declared that their legislature should "make no law respecting an establishment of religion, or prohibiting the free exercise thereof", thus building a wall of separation between church and State."
Thomas Jefferson


 "Fix reason firmly in her seat, and call to her tribunal every fact, every opinion. Question with boldness even the existence of a god; because, if there be one, he must more approve the homage of reason, than that of blindfolded fear."
Thomas Jefferson in a letter to Peter Carr


A Government founded upon justice, and recognizing the equal rights of all men; claiming no higher authority for existence, or sanction for its laws, than nature, reason, and the regularly ascertained will of the people; steadily refusing to put its sword and purse in the service of any religious creed or family, is a standing offense to most of the Governments of the world, and to some narrow and bigoted people among ourselves.
Frederick Douglass






On Wed, Aug 5, 2020 at 8:36 PM Rick - N7WE <n7we1980@...> wrote:
Ron-
I'd suspect common mode RFI.  Lots of info available.  Google "common mode rfi on end fed antenna".  If I'm right, a properly placed choke should fix it.  Good luck.
--
Rick - N7WE
070 - #1602