[Elecraft] HF amp kits

[Jozef Hand-Boniakowski]

I have been a ham for 43 plus years (12/23/63) and up to now have not 
heard of any such limitation.

Jozef WB2MIC

David Wilburn wrote:
> Just working from memory here, but wasn't there also a limit that the 
> amateur could only build one such amp a year?
>
> David Wilburn
> dave.wilburn at verizon.net
> K4DGW
> K2 #5982
>
>
> Jim Wiley wrote:
>> The 15 db rule applies only to manufactured for sale amplifiers.  It 
>> does not apply to amplifiers that an individual ham builds for him or 
>> herself, particularly when a a kit is not involved..  Section 97.317 
>> of the rules, which is where the 15  db rule appears, applies to the 
>> certification of external RF power amplifiers that a manufacturer 
>> offers for sale.  Home-made amplifiers do not require certification.  
>> They must still meet some standards, such as those involving purity 
>> of emissions (harmonics, for example) and of course must not be 
>> operated above 1500 watts PEP, but that's pretty much it.
>>
>> I am unsure of how the rule applies to kits, but I think they would 
>> be considered a "manufactured product" if all the parts needed to 
>> complete the amplifier are contained, in the kit.  If, however, a 
>> "kit" contained only some of the parts, and could not in itself be 
>> assembled into a working amplifier without adding extra parts, then 
>> the certification rule probably  would not apply.
>>
>> It would be perfectly legal for a ham to build a home-brew 
>> grid-driven amplifier that  could take  the 10 watt signal from his 
>> K2 and boost it  to 1500 watts output.  Such an amplifier would have 
>> (roughly) 22 db of gain.   A pair of 4CX800 tubes could accomplish 
>> this, I think.   Remember also that the old Johnson Thunderbolt could 
>> be operated in grid-driven mode, and it had (still has, if you can 
>> find one) similar performance, using a pair of 4-400 tubes.
>>
>>
>> - Jim, KL7CC
>>
>>
>>
>>
>>>
>>>> Chris Kantarjiev wrote:
>>>>
>>>>>
>>>>> The Linear Amp kits seem to need a fair amount of drive. I've been
>>>>> idly thinking about a linear that would allow me to drive it with
>>>>> my barefoot K2 and get 600-800 watts out for CW.
>>>>
>>>
>>> The limit is 15 dB and is still in the requirements despite the  
>>> recent loosening of Part 97.  That should give something over 400  
>>> watts when driven by a K2. I don't recall whether the "easily- 
>>> modifiable" rule is still there, so it may be possible to have an 
>>> amp  with an attenuator on the front-end (I heard that one of the 
>>> Tokyo  High Power amps does this, but haven't verified that).
>>>
>>> 73, Bob N7XY
>>>
>>>
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