Great idea Pete but I also may run head long into false positive
results with so many Beverages (12) and each with a different possible
indications. Here with the masking over of any subtle changes by
strong ever present boiling tropical QRN yielding a possible infinite
number of variables, each by themselves variable may not quickly yield
any discernible results. If there was any time day or night when QRN
did not run S-9 in almost every direction I would give it a try but I
fear that with what i have I may be just peeing up a rope.
Herb, KV4FZ
On 6/20/2012 4:45 PM, Pete Smith N4ZR wrote:
> Doesn't this suggest that there is a role here for cut and try? Take a
> set of clip leads to the base of the tower and experiment?
>
> 73, Pete N4ZR
> The World Contest Station Database, at www.conteststations.com
> The Reverse Beacon Network at http://reversebeacon.net, blog at
> reversebeacon.blogspot.com,
> spots at telnet.reversebeacon.net, port 7000 and
> arcluster.reversebeacon.net, port 7000
>
> On 6/20/2012 3:45 PM, Herb Schoenbohm wrote:
>> Tom,
>>
>> This is not encouraging news for those of us with towers already ground
>> and are either shunt fed or cage fed. Even though they are not
>> resonate, although top loaded and approaching resonance, it seems that
>> even with some elaborate decoupling arrangements, and I hope I am wrong,
>> not to much can be gained by even trying to get them "detuned". This is
>> crucial for me to know, and I would assume many others that have
>> Beverage terminations or feed points 100 feet away,
>>
>> Thanks for the warning as this summer I was going to install a HV relay
>> on the shunt cage to ground....but as you point out it may not help as
>> the grounded shunt or cage fed tower is already a noise source for close
>> proximity RX antennas.
>>
>>
>>
>>
>> On 6/20/2012 2:09 PM, Tom W8JI wrote:
>>> There are two potential problems with this. As general rules:
>>>
>>> 1.) Grounding any antenna which is dependent on a ground system to be
>>> resonant will maximize reradiation.
>>>
>>> 2.) Resonant elevated radials, even without an antenna connected, are
>>> resonant and re-radiate.
>>>
>>> 3.) Things that are not resonant can still re-radiate.
>>>
>>> To minimize coupling from a resonant radial, the radial has to be
>>> disconnected from ground and from other radials.
>>>
>>> Different systems can be different, and in some cases re-radiation can
>>> actually cause a null that reduces noise, but the general rule is
>>> self-resonant antennas with a ground (Marconi), or nearly self-resonant
>>> antennas when grounded, should be floated. Other antennas can be terminated
>>> in an inductor, capacitor, or opened, depending on the system.
>>>
>>> My 220 ft insulated tower, in the center of a four square, is "opened" by
>>> shorting a specific length of coax to the "L" matching network. It has much
>>> more radiation when open or grounded. radiation is minimal when detuned by a
>>> proper impedance.
>>>
>>> 73 Tom
>>>
>>>
>>>
>>>
>> _______________________________________________
>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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