[Hallicrafters] HT-44 questions

[Waldo Magnuson]

Hi Fern,
    You are correct - I just checked the HT-44 schematic and the output 
tubes ARE wired in series.  The manual procedure given in Section 9-4 
(Matching Output Tubes) makes no sense.  I've been warned to watch the 
screen current if I disconnect the plate cap so I will check what could 
happen before doing so.
    Thanks for responding.
73,  Skip  W7WGM

On Sunday, April 2, 2006, at 08:50  PM, Fern Rivard wrote:

> Hi Waldo:
>    If the filaments of the final tubes are wired in series, then 
> simply disconnect one plate cap at a time to verify the idling current 
> of each tubes. Otherwise, unplugging one tube at a time (if filaments 
> are wired in series) will result in "no emission" in either tube!    
> Fern
>
>
> ----- Original Message ----- From: "Waldo Magnuson" <magnuson at mac.com>
> To: <hallicrafters at mailman.qth.net>
> Cc: "Waldo Magnuson" <magnuson at mac.com>
> Sent: Sunday, April 02, 2006 8:55 PM
> Subject: [Hallicrafters] HT-44 questions
>
>
>> I got my SX-117 restored to original configuration and it performs 
>> good.  So I moved on to my recently acquired HT-44.  After cleaning 
>> up the internal antenna relay installation I applied power following 
>> the Tuning Procedure.  The first thing the manual mentions is to 
>> adjust the bias before proceeding with the Basic Tuning.  I checked 
>> it according to section 9-3 in the manual and it adjusted nicely to 
>> one volt (100 MA) idling current for the finals just like the manual 
>> states.  It looked so good that I did a Final Tube Matching check 
>> (section 9-4). The manual states to pull one final tube and adjust 
>> the Bias to 0.5 volts (50 MA) and then swap tubes and they should 
>> check to within 0.1 volts).  Well the problem with either tube in 
>> either socket I get NO bias reading.  I checked both output tubes 
>> (6DQ5) with my tube checker (Hickok 6000A) and both check normal.  
>> When I try to do the Basic Tuning I get no RF output.  Why do I get 
>> the correct idling current but nothing else?  Any thoughts on what to 
>> check next?  Thanks.
>> 73,  Skip  W7WGM
>>
>> ______________________________________________________________
>> Hallicrafters mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/hallicrafters
>> Help: http://mailman.qth.net/mmfaq.html
>> Post: mailto:Hallicrafters at mailman.qth.net
>> ----
>> List Administrator: Duane Fischer, W8DBF **for assistance**
>> dfischer at usol.com
>> ----
>> Hallicrafters Collectors International: http://www.w9wze.org
>>
>>
>> -- 
>> No virus found in this incoming message.
>> Checked by AVG Free Edition.
>> Version: 7.1.385 / Virus Database: 268.3.4/299 - Release Date: 
>> 3/31/2006
>>
>