[Amps] Henry 4K Ultra

Bob Maser bmaser at tampabay.rr.com
Thu Jan 5 00:50:19 EST 2006


Thanks for the info Steve.  I have already seen those pics.  I adjusted 
everything for 20M today, taking off the chain and adjusting everything 
separately and got it working really great...on 20M.  Then I tried 
reconnecting the chain and dropping down to 75 and the input SWR was really 
high and the output was way off.  I go back to 20 and everything is still 
good.  Since I don't know what parameters the folks at Henry used to design 
the Pi-L output and the input, it makes it very difficult to synchronize 
everything.  Tomorrow I am going to call LDG Electronics and see about 
ordering a V100 Pro auto tuner for the input of this amp.  That will leave 
only the 2 L's and C1 traveling at the same time which should simplify 
things a lot.  This is what W8RA did with the new 3CX1500D7 amp that 
appeared in the 2006 ARRL Handbook and he was happy with the results. 
Another thing that bothers me is that if the ganged capacitors that are in 
the input circuit ever go belly-up,  I have been told that they are no 
longer available.  By removing all of the components in the input circuit, 
it makes it real simple.  Also, can probably peddle the parts to somebody 
that has a broken 4K Ultra.  Then I will have brought the amp into the 21st 
century.

Thanks,
Bob  W6TR
----- Original Message ----- 
From: "Steven Cook" <sccook1 at cox.net>
To: "Bob Maser" <bmaser at tampabay.rr.com>
Sent: Wednesday, January 04, 2006 11:49 PM
Subject: Re: [Amps] Henry 4K Ultra


> Bob,
>
> http://members.cox.net/kj7e2/4k_ultra.htm
>
> I came across this website today.  The photographs are very good and show 
> the bottom of a 4K Ultra.  You can see the L-Section Coil and the Input 
> Tuning Capacitors.  You may get some ideas on how things should be 
> arranged.
>
> Let me know it this helps...
>
> Steve
>
>
>
> ----- Original Message ----- 
> From: "Steven Cook" <sccook1 at cox.net>
> To: "Bob Maser" <bmaser at tampabay.rr.com>
> Sent: Monday, December 26, 2005 11:36 PM
> Subject: Re: [Amps] Henry 4K Ultra
>
>
>> Another idea...
>>
>> Do a search on the internet on the Henry 4K or Henry 4K Ultra and note 
>> all hams who own one.  Look up their e:Mail addresses on QRZ.com and send 
>> them an e:Mail.  Perhaps someone who owns one has been down this path 
>> before.
>>
>> Steve
>>
>>
>> ----- Original Message ----- 
>> From: "Bob Maser" <bmaser at tampabay.rr.com>
>> To: "AMPS" <amps at contesting.com>
>> Sent: Monday, December 26, 2005 11:21 PM
>> Subject: [Amps] Henry 4K Ultra
>>
>>
>>>I am still wrestling with the alignment of my 4KU.  I am told that the 
>>>4KU's
>>> that were sold to the military were supplied with a "Service Manual" 
>>> that
>>> had much more info regarding how to set up the gang tuned circuitry that 
>>> is
>>> adjusted as the Tune control is turned.  The regular Operating and
>>> Maintenance manual that accompanied the civilian amps did not cover 
>>> this. I
>>> would really like to hear from someone that has this info.  I suspect 
>>> that
>>> Henry did not use 300 ohms as the intermediate impedance between the Pi 
>>> and
>>> the L of the tank circuit.  The reason I think this is because when I 
>>> set up
>>> the L inductor for a specific band, it does not track properly as the
>>> frequency is changed.
>>>
>>> Any help would be greatly appreciated,
>>>
>>> Bob  W6TR
>>>
>>> _______________________________________________
>>> Amps mailing list
>>> Amps at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>> 



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