[Amps] Recommended Tuner for Clipperton L

[Roger (K8RI)]

On 2/2/2014 2:11 PM, qrv at kd4e.com wrote:
> Weird amps list error the first try - trying again ...
>
>> Roger,
>>
>>      Would you please explain "hiss"?

iss as in hi voltage arc.  Sounds just like a cat or snake.

>>
>>      What, precisely, is happening to create that sound?

If the antenna in highly reactive (inductive) and the SWR is high the 
voltage goes high.
Neither the MFJs or Dentrons had a high enough voltage rating for much 
over what I'd get when the 160 antenna was resonant near the DX window 
and I'd go to the top of the band.

Moving the resonant point to the middle, or upper end of the band would 
eliminate the arcing at 1 KW, but then I had concerns about the small 
wire on the rotary inductor when operating at the bottom end of the band.

They really needed a higher voltage rating on a larger cap and a larger 
size wire on the rotary inductor for current on low impedances.

73

Roger (K8RI)

>>
>>      There are so few parts involved it seems that there's
>> either too small inductance (or perhaps the gauge of the coil
>> wire is undersized), too little capacitance (or perhaps aging
>> doorknob capacitors), or a tiny arc across an under-rated switch?
>>
>>      Could it be that a small tweak to one part of the mix of
>> parts could compensate for the weakness elsewhere e.g. adding
>> capacitance balances the added stress at 160m such that the
>> marginal coil or switch is not pressed to the limit?
>>
>>      Trying to understand the "why" behind the symptoms ...
>>
>> Thanks!
>>
>> David
>>
>>> I've had no problems with the half sloper, center fed droopy dipole
>>> on 160, or the Fan Dipole on 75.  The Dentrons and MFJ 989 series
>>> would all "hiss" at me on 160 near the top end of the band at much
>>> over 1 KW out.
>>>
>>> 73,
>>>
>>> Roger (K8RI)
>
>
>


---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com