[Elecraft] OT: Remote antenna tuner

[Fred Jensen]

I also disagree.  AM broadcast verticals are designed to achieve a 
desired pattern and main lobe elevation angle.  Over flat ground, 225 
degrees will optimize the ground wave coverage.  However, higher powered 
stations will then suffer from self-interference at the coverage edges 
because the sky wave and ground wave interfere.  It's common to shorten 
the antenna a bit to perhaps 195 degrees or so which tends to reduce the 
self-interference.  Once the pattern and main lobe angle have been 
defined, the feed point is matched to the transmission line with an 
appropriate network.  Neither 225 degrees [5/8 wave] nor 195 degrees are 
resonant lengths and both require a matching network.

Many hams do not have the luxury of resonant antennas on every band.  It 
seems perfectly reasonable to employ some sort of matching network to 
match the feed point to the coax on bands where it is not resonant 
AND/OR does not present a 50 ohm load to the coax and needing to do so 
does not imply there's something wrong with the antenna.

73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 3/31/2019 9:44 AM, W2xj wrote:
> I would disagree. Most high power commercial operations use non-resonant mismatched antennas. Typically there is either a tuner at the antenna or open wire is used.
>
> Sent from my iPad
>
>> On Mar 31, 2019, at 12:13 PM, Ken G Kopp <kengkopp at gmail.com> wrote:
>>
>> If an antenna is showing a VSVR of 3:1, something about the situation
>> is wrong, and most likely it's -not- the antenna.  Fix the problem … feed
>> the antenna power where it's resonant, assuming the antenna is actually
>> resonant on the amateur band of interest.  Expecting a tuner to compensate
>> for a problem external to an antenna is unreasonable, IMO
>>
>> 73!
>>
>> Ken - K0PP
>>