[TowerTalk] "experts" on loading towers on low bands

Mark - N5OT r-emails at n5ot.com
Sat Sep 14 06:57:49 EDT 2019


Wow.  I attend to important things for a couple days and look what happens.

I think some of you may have missed "intended to be humorous" in my 
initial post.

Dave here is putting words in my mouth.  I have plenty of understanding 
and have a mass of excellent data on which to draw. I just approach 
things differently than some other people reading this, and I arrive at 
conclusions I find satisfactory.  That is really all that matters to 
me.  I may also have different design goals.

Good day,
Mark N5OT


On 9/10/2019 6:11 PM, David Gilbert wrote:
>
> Not to beat a dead horse, but no ... you aren't saying the same thing.
>
> N5OT said to just build it and see if it works "good enough", without 
> further understanding or even without anything to compare it against.
>
> Conversely, you said you relied on the K6STI's model to "do your 
> homework ahead of time" and that you trusted the model over someone 
> else's experience whether or not it was good enough.
>
> Those are opposite approaches whether you recognize it or not, and for 
> the record I would have done what you did as opposed to N5OT's 
> approach.  I'm a firm believer that as practitioners of a technical 
> hobby we should make an effort to understand the science of what we're 
> doing BEFORE we make the tradeoff decisions of cost, time, effort, 
> hassle, need, probability of success, etc.
>
> Dave   AB7E
>
>
>
> On 9/10/2019 3:24 PM, Bob Shohet, KQ2M wrote:
>> Actually we are saying the same thing.
>>
>> 1) Build it and put it up!
>>
>> 2) Take it down or adjust it and put it back up again.
>>
>> 3) Repeat as needed.
>>
>> 4) Get on and make lots of q’s and have fun
>>
>> In each case you clearly have a specific design in mind – a model or 
>> plan whether computer generated, hand drawn or something else, with 
>> measurements that we use to build what we put up.  We don’t just 
>> invent it in our head with random materials and random measurements 
>> and slap it together.
>>
>> In addition, while modeling programs are based on math and theory, 
>> they are far from absolute; especially when dealing with terrain 
>> where the measurements are not absolute either.  And all computer 
>> programs have points of inflection where the results change greatly 
>> based on the tiniest of dimension changes and those dramatic result 
>> changes are artifacts of software program limitations.  Anyone who 
>> does a lot of computer modeling knows that.  Theory is not the same 
>> thing as reality.  Modeling programs are “guestimates” at best.
>>
>> The rest of your comments are not worthy of a response.
>>
>> Bob  KQ2M
>>
>>
>> From: David Gilbert
>> Sent: Tuesday, September 10, 2019 6:01 PM
>> To: towertalk at contesting.com
>> Subject: Re: [TowerTalk] "experts" on loading towers on low bands
>>
>>
>> You and N5OT aren't saying the same thing at all.  He said to just
>> experiment and see what works well enough to be acceptable, while you
>> said you ignored the practical experience of other hams (stuff that
>> "works" or doesn't) and instead used a modeling program (which is based
>> purely on math and theory) to make your decision.
>>
>> It's odd to see two guys pat each other on the back for reinforcement
>> when they don't even understand they have opposite stances. Whatever
>> happened to logical thinking?
>>
>> Dave   AB7E
>>
>>
>> On 9/10/2019 1:44 PM, Bob Shohet, KQ2M wrote:
>>> Mark has nailed it!
>>>
>>> One of the nice things about making something and seeing it it works 
>>> well enough is that what you make doesn’t know how well it is 
>>> supposed to work and doesn’t care.  :-)
>>> So if it works it works regardless of what anyone thought beforehand.
>>>
>>> Usually if it works (and no one thought it would), we find out long 
>>> after the fact why it worked, and generally it was something that 
>>> wasn’t known or understood at the time, and now the field advances 
>>> with the “Gee, I wonder why it works so well?” study and discoveries 
>>> afterwards.
>>>
>>> Simple example...  I wanted to put up a 4-stack on 15 meters when I 
>>> built my station.  I new that I needed heights of 30’, 60’ and 90’, 
>>> but with 100’ of tower it didn’t seem to make sense to put another 
>>> 15 above that.  The thinking was that even on a tall mast, the 90’ 
>>> and another 15 at 109’ would be too close and would phase poorly 
>>> especially if they were pointed in different directions.  Everyone 
>>> that I asked about this said so.  These guys built great stations 
>>> and are great ops.  You know all of their calls.  But I modeled the 
>>> stack with K6STI’s YO and it looked GOOD!  I asked them again. “NO!  
>>> I would not do it” came the answer in unison. Thankfully I did my 
>>> homework beforehand and I chose not to listen to the advice of 
>>> people that I respect.
>>>
>>> So I built it and put it up anyway.  The 5L at 109’ was and is a 
>>> KILLER!, especially when in phase with the 90’.  I believed the 
>>> modeling over my terrain.  The software was correct and my 15 meter 
>>> experience has been awesome for the past 20 years. (And I have 
>>> thanked Brian, K6STI many times over the years)
>>>
>>> Before I put it up I reasoned that if it didn’t work I could always 
>>> take it down.  But if it did work, I would never want to!  :-)   
>>> Very high reward to risk ratio!
>>>
>>> Moral of the story:  Model it, build it well, put it up and see how 
>>> it does!
>>>
>>> 73
>>>
>>> Bob KQ2M
>>>
>>>
>>> From: Mark - N5OT
>>> Sent: Tuesday, September 10, 2019 4:11 PM
>>> To: towertalk at contesting.com
>>> Subject: Re: [TowerTalk] "experts" on loading towers on low bands
>>>
>>> I'm a big fan of "experiment trumps theory" and basically I have spent
>>> nearly 50 years doing the following:
>>>
>>> 1. Make something.
>>> 2. See if it works well enough.
>>> 3.  If it works well enough, you're done.  If it doesn't, change
>>> something and see what happens.
>>>
>>> Clearly I'm just an amateur.  But because I'm on TowerTalk™ I can say I
>>> make "educated guesses."
>>>
>>> Love you guys,
>>> 73 - Mark N5OT
>>> (intended to be humorous - everyone carries a bucket of gasoline in one
>>> hand and a bucket of water in the other - they get to choose which one
>>> they throw on the fire - I choose water) (most of the time)
>>> _______________________________________________
>>>
>>>
>>>
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