[Heathkit] AT-1 Question

[Garey Barrell]

My first "DX QSL" as KN4OAH in Louisville KY was from Grand Island, NE.  Thanks 
to my "link coupled" QSL 40 single 6L6 transmitter.  Of course I was on 80M and 
the "QSL" was for 40M, but ...

Unfortunately, my frequency on 40M was at 7450 kHz, well outside the Novice, 
(even the Amateur!,) band.

By the way, Grand Island NE was home to the FCC Monitoring Station.

73, Garey - K4OAH
Atlanta

Mark S Graalman wrote:
>   Some experiments here indicate the link coupling, if done
> rather loosely  such as at the cold end of the tank provides about
> 20 dB at the second harmonic. A far cry from a pi-network, but
> if the link output is run into an 50 ohm I/O output filter then
> the performance is pretty good. So you could preserve the AT-1 by 
> just running it into a 50 ohm I/O pi network, or even better a half wave
> filter. But you'd have to build a filter for each band you intend to
> operate.
>  I've built critical coupled link outputs feeding half wave filters here 
> while prototyping no-tune amplifiers and 60-65 dB at the second
> harmonic was obtainable without much trouble.
> 
> Mark  WB8JKR
> 
> 
> On Thu, 22 Jan 2004 23:03:06 -0500 Garey Barrell <k4oah@mindspring.com>
> writes:
> 
>>Joe -
>>
>>The link coupled output does NOT have the harmonic suppression 
>>provided by a 
>>Pi-Net.  I used to have typical numbers, but long forgotten!  :-)
>>
>>That said, it is pretty difficult to match anything but a resonant 
>>antenna with 
>>link coupling, so you usually end up with an antenna tuner anyway!  
>>The Heath 
>>AC-1 was offered by Heath to address this need, but it cost half as 
>>much as the 
>>transmitter, so most (poor!) hams just kludged something together. 
>>With the 
>>result that the AC-1 is even more scarce today than the AT-1.  The 
>>AC-1 included 
>>a low pass filter AND and LC matching network AND a neon "output 
>>indicator".
>>
>>73, Garey - K4OAH
>>Atlanta
>>
>>
>>
>>Wj5mh@aol.com wrote:
>>
>>
>>>It appear the AT-1 has a link coupled output.  What is the 
>>
>>harmonic 
>>
>>>suppression characteristics compared to a pi-section output?
>>>
>>>Thanks,
>>>Joe
>>>
>>>
>>
>>
>>_______________________________________________
>>List Administrator: Duane Fischer, W8DBF        
>>** For Assistance: dfischer@usol.com **         
>>$$ See the vintage area on the HCI web site - http://www.w9wze.org 
>>$$ 
>>Heathkit mailing list
>>Heathkit@mailman.qth.net
>>http://mailman.qth.net/mailman/listinfo/heathkit
>>
> 
> 
> 
> ________________________________________________________________
> The best thing to hit the internet in years - Juno SpeedBand!
> Surf the web up to FIVE TIMES FASTER!
> Only $14.95/ month - visit www.juno.com to sign up today!
>