[Elecraft] Elecraft Product Ideas

[N2EY at aol.com]

In a message dated 5/22/06 8:38:50 AM Eastern Daylight Time, 
ncsailors at yahoo.com writes:


> As I said before, I DO NOT want to install an
> hf amplifier INSIDE my K2.   A nice outboard amp
> would suit me.  

As others have already pointed out, just build the KPA100 in an EC2 
enclosure,
Elecraft can't offer that as a kit, but you can homebrew/modify it.

> 
> The FCC, and probably the 11m CB'ers, haven't made
> this easy.
> 

It's been that way since 1978. Perhaps the rules will change, but I would not
count on it any time soon because FCC takes a while to make Part 97 changes.


>  I'm quite sure I know
> more about CMOS, bipolar and analog IC design/fab/test
> - than I do about Tube technology.


Tubes are high voltage/low current devices. Different game than
silicon. 

> 
> I do not understand the design constraints of
> creating a linear HF amplifier.  

I do. 


All I know is
> 
> the tube amps of a generation back, along with
> the 2006 tube maxi amps (KWatt) of today - all seem
> to have relatively simple circuits.  
> 

Yes, they did. That's because:

1) They could use one or two active devices rather than many
2) They required manual adjustment of the output filter/matching network
3) Most of them had no RF feedback and no real protection against
operator error


> Intuition tells me - a 6146 TUBE amp box, designed
> right, powered right - would be a very useful
> amplifier addition - and would earn respect to
> those who heard it on the bands.  

Where I work, we have a saying:

"The track circuit does not care how you feel"

What's to knock?
> 
> And I have to believe it could be relatively
> small.
> 

Compared to what? A pair-of-6146s amplifier has to be
at least twice the size of a K2 in order to hold the 
necessary parts. 


> As a list member of several IC-7000 and IC-706MKIIG
> BB groups - these hams regularly complain about
> solid state final problems in these 2006 rigs.
> Icom's lack of replacement devices, mysterious
> problems, failures, $300 replacement Icom service
> charges .... "heat" problems, are all common topics on
> these boards.   In all, over past 10 years I've
> owned (3) IC-706MKIIG's, and (1) IC-7000 (winter
> 2005 when they came out).
> 

Those are two models by one manufacturer, both of them
super-compact rigs. The problems cited are an indication
of trouble with that particular design, not SS finals in general.


> But alas - I like the smell of solder, like to 
> build things with my hands.  

Then get a junker HW-100 or similar Heath rig, and rework the PA section 
as an amplifier. There's an article on how to do it on the Elecraft website. 
If you don't want the entire rig taking up desktop space, rebuild the PA 
section in a smaller cabinet. 

And my intuition
> 
> usually serves me well.
> 

"The track circuit does not care how you feel"


> Anyone out there - think a 200Watt PEP tube
> 6146 amplifier - would cut it with a K2?  
> Why?  Why not?  

Depends what you mean by 'cut it'.


> Why couldn't Elecraft, design and market one?
> 
It could be designed.. But:

1) Such an external amplifier could not be certified under current FCC rules. 
It would have to be internal. That means a much bigger case than the K2 now 
has.

2) The parts cost would probably be much more than a KPA100, particularly if 
a power supply (12 volts DC or 120 volts AC) were included. 

3) Manual tuning would be required.

4) The finished product would compete with an established Elecraft option. 


73 de Jim, N2EY