[Hammarlund] HQ-145 misprint or what?

[Joe Connor]

Gary:

Do you have access to the Sams schematic? When I see something like this, I try to compare the schematic in the manufacturer's manual with the Sams schematic. If they're both the same, a wiring error is more likely. If the Sams matches what you see in your radio, then a misprint in the Hammarlund manual is more likely.

Joe Connor



On Sunday, March 23, 2014 8:45 PM, Kenneth G. Gordon <kgordon2006 at frontier.com> wrote:
 
Although I have not yet looked at my HQ-145 manual, what Richard says 
>below makes perfect sense.
>
>From your description, it sounds to me as though there is some problem 
>OTHER than the one you have so far found.
>
>Ken W7EKB
>
>On 23 Mar 2014 at 9:25, Richard Knoppow wrote:
>
>> These radios were done by hand. Early in the production 
>> process, they probably did not have all the "normal 
>>  mistakes" cataloged for the inspectors. What you have is a 
>> prime example of how a test escape trashes the company´s 
>> reputation rather than getting fixed in the field.
>>
>>      A little more. I think the 6.8meg resistor belongs as 
>> shown in the BAMA manual, that is from cathode to grid or 
>> pin-1 to pin-7.  Its purpose evidently has to do with the 
>> manual RF gain. If it goes from pin-6 to pin-7 it puts some 
>> positive voltage on the cathode from the screen grid.  I 
>> can't see why this would be done. Note that the S meter 
>> measures the difference between the cathode current of V-4, 
>> which is on the AVC bus and V-5 which has fixed bias and 
>> will have pretty constant cathode current. So, anything that 
>> affects the current of V-4 will affect the way the S meter 
>> reads.  Have a look at the BAMA manual and compare it to 
>> what you have. I am pretty sure there are other, higher 
>> resolution, manuals on the web.
>>      Again, 2.2K is probably the right value for the 
>> resistor to the screen grid at pin-6 and 470K the right 
>> value for the control grid resistor to pin-1.
>
>Ken W7EKB
>
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