Remote antenna sw

Its in the mail ...

I am going to run the existing 30 meter Vertical through this switcher then I am planning on adding a 30 meter dipole for comparison.   Not sure if I will do 2 more different 30 meter antennas but I do know one thing for sure its going to be really cool.  If this switch works out I am going to get the larger one with more inputs plus VHF/UHF capabilities for the top of the hill.  

14AVQ Troubles

 The 14AVQ vertical is not working well so I was reading on the internet and someone suggested taking ti apart an cleaning the traps and what not.     Its seems to work OK on 10m and 15m but  the TS690s really doesn't like the antenna on 20m and 40m.   The old FT101e  didn't mind the old antenna bit its not the same with teh new rig.       The 14AVQ VSWR on 10m is great ,  1.2:1 @ 28.1 MHz ... 15m is similar but 20 and 40 nothing below 2:1 VSWR.  

Thought I nailed the fault right off the first trap above the 10m section had a tab broke off the cover ...

So I came up with this fix ...

Also found something growing under the second trap ...

Cleaned everything up and put it all back together...

Unfortunately  it did not make much of a difference!    There is a very good possibility it may have something to do with the 500' run of LDF4 cable to the top of the hill where the antenna is located.  The next step is to try the antenna closer to the house with a different IFL.

Inspite of questionable performance on 20 meters I used the TS590s to make an SSB contact on 20 meters .... an ever so brief QSO with a guy in Cuba.

Attenuation due to tress at HF

I sure do know the effects of Trees / Vegetation at Microwave Frequencies but I really do not know much about the effects at UHF/VHF and HF below 30 MHz.   I know that there would be some affect at VHF/UHF and that it would significantly decrease as you get down to the HF band.  So I googled the topic and here is what I found......

Ora E. Smith:
There is book called "HF Communications: A Systems Approach" by Nicholas Maslin (1987, I think) that addresses the issue briefly.  My interpretation of what he says is that vegetative attenuation negligible below 2 MHz, but can be a major factor at 30MHz.   A curious result of his analysis is that for ground wave propagation through vegetation, the loss below 30MHz for a given frequency is essentially constant and independent of distance -not sure I follow his thinking, but that seems to be his conclusion. The only way I can make sense of that is to conclude that wave propagation extends above the tree line and that the attenuation occurs mostly in the antenna near field, but that is not his explanation. If my version of this is true, it would seem that unless you are operating in a very tall rain forest, getting the antenna a few wavelengths away from trees so none of them are in the nearfield would reduce attenuation effects markedly.  Also, objects in the near field are able to distort the radiation pattern of the antenna considerably, unlike far field objects.

If you're talking about skywave attenuation, then it seems that you would want the antenna to have a clear view out to a few wavelengths, according to my theory anyway.

At 30MHz he states that the standard deviation of loss (so this must be based on either some kind of data or lots of simulation runs) is on the order of 4 db through bare trees, and 7 db through leafed trees.  Loss increases exponentially with frequency, he says, and is negligible by the time you are down to 2MHz.  I generally try to stay away from trees except as antenna supports, and I have found that operating portable in the woods is difficult, though it's hard to separate out all the other portable antenna shortcomings from the tree influence.

Do trees attenuate HF signals? « Reply #8 on: October 21, 2003, 01:19:10 PM »

---

Yes and no!
Trees and plants do attenuate HF signals.
I found out that maïs does attenuate a lot on 10m. Just use your 10m HT or mobile setup near a maïs-field and you'll notice the attenuation of the received signals.
When you're using a 80m antenna near trees it will have (almost) none influence.
This is not a scientific study, but just the things I personally discovered.

73 de ON4MGY Nic

Trees have fairly minimal effect on HF propagation.

Trees touching your HF antenna will tend to ground out the antenna.  The more touching points, and the wetter, the more signal you will lose.   Foliage touching at high voltage points can and has caught fire!  There are a number of posts here and on the other board in the last couple years, some with photos, to attest to this.

An insulated wire vertical could be hauled up alongside a trunk and avoid the grounding problems.  Stake out some radials at the base.  Very stealthy and neighbor friendly.



"Trees
As potential hazards these are usually much overrated. Horizontally polarized antennas can usually be more or less buried in trees with little or no effect"

Here is my added advice, Use INSULATED wire, do not use bare wire....

For HF, any attenuation will be essentially unmeasurable by any equipment the average ham is likely to have. Wires in the trees are common and work quite well.

As the frequency goes up past 50 mhz, the attenuation will be more and more of a factor and will be measurable. For 2m/440, higher is not only better, the antennas really need to be above the trees, unless all you are doing is hitting local repeaters. For weak-signal work height and tree clearance are everything.

30m 1/4 GP Pictures

Base ...



















Base with weather seal ...  ( note N Connectors temp seal )

























Vertical element  -  its a black wire so I added a RED Line to the left of the wire ...

There are a few outstanding things that I want to do with this antenna...

#1 - Remove Rope ,  add pulley and small counter weight at top to account for tree swing in the wind. Another thought I had about that was just to fix the vertical element to the tree.    ( Going to try that with a future ground mounted vertical )

#2 Run through and Antenna Swicther ... when I purchase it!

#3 Weather proof  the "N Connector "

#4 Lob off N connector in shack and connect to the PL259 female Patch Panel

On 30 Meters

Built a 1/4 wave ground mounted vertical antenna for 30 Meters.   There are 4 radials 23.2 feet and the vertical element started off the same but it ended up a foot or  two two shorter when I tuned it.    At 10.1 MHz I ended up with a VSWR of 1.1 : 1  and the TS690s antenna tuner liked it rewarding me with 80 Watts of CW power.  

 30 Meters was quite appealing to me...

- Great propagation throughout the solar cycle
- Its CW and narrow band digital from 10.100 MHz all the way to 10.150 MHz .... all 50 kHz of it!
-1/4 Wave is 23.2 feet ... small antennas.  

Made 2 contacts ...

 So the new to me TS690s is a real gem.  Best receiver I have ever had.   It goes all the way down to a few hundred KHz and has continuous coverage!     I have to beef up the power supply a bit.  The radio requires 20 am / 12V and I have a supply that is providing that but it gets quite warm.   I have a home brew supply that I think is big enough but I want to burn it in for a bit before using it.     I am still in the process up reorganizing the shack ... lots of stuff goes ,  it will be really cool when I am done.

Future purchase - remote sw

New Toy

Its been a couple of decades since I purchased a HF Radio ...let the games begin!