[AMPS] PA Recommendation Wanted

[Rich Measures]

>
>On Fri, 06 Jun 1997 23:34:55 GMT wrt@eskimo.com (Bill Turner) writes:
>>On Fri, 06 Jun 1997 10:36:03 EDT, km1h@juno.com wrote:
>>
>>>I guess the question I have is why anyone would wish to give up a 
>>bullet
>>>proof workhorse amp such as the AL-1200 for something completely 
>>unknown
>>>with no track record such as the QRO?
>><snip>
>><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
>>"Bullet proof" is in the eye of the beholder I suppose, but my
>>experience would rate it a bit more tender than that.
>>
>>The AL-1200 is probably fine for CW/SSB operation, but running it at
>>full power on RTTY will overheat the tank coils on 80 and 160 meters.
>>There is nothing in the manual to caution you against this. During a
>>recent contest, mine got hot enough to melt the solder connecting the
>>80 meter tap.  The plastic support rods also melted and the coil
>>twisted itself into a pretty good slinky imitation.  It needs more
>>cooling air in the tank area.  Cost about $25 for a replacement coil.
>>
This isn't surprizing to me, Bill.  The designer of the AL-1200's tank 
has made some eyebrow-raising statements regarding RF skin-effect. 
 Consider the ratings of the E.F Johnson (now made by Multronics) roller 
inductors.  (silver-plated) #12 wire is rated at 5a.  1/4" by 1/8" bar 
stock is. rated at 10A.  1/2" ribbon is rated at 15A. 
  I chuckled when the AL-1200's designer recently criticized the SB-220's 
cooling system.  Heath had enough smarts to direct cooling airflow at the 
tank inductors.  He did not.  
Rich---

R. L. Measures, 805-386-3734, AG6K   


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