[ARC5] BC-455 not working

[kg4kgl at gmail.com]

I did not really tweak any settings other than two move the trimmers to break lose any oxidation. Socket have been sprayed and cleaned gear drive on tuning cap has been lubed. 

I will check for cold tube, either a bad one or an incorrect filament wiring job. All but the mixer tubes are known good ones as I borrowed them from the working bc-454. 

Robert

Sent from my iPhone

> On Jan 13, 2018, at 19:41, Tom Lee <tomlee at ee.stanford.edu> wrote:
> 
> At the risk of sounding like a broken record, did you check the easy stuff first? Tweaking a bunch of RF/IF stuff without having done so could leave you with a bigger problem than you started with.
> 
> Just sayin'.
> -- 
> Prof. Thomas H. Lee
> Allen Bldg., CIS-205
> 420 Via Palou Mall
> Stanford University
> Stanford, CA 94305-4070
> http://www-smirc.stanford.edu
> 650-725-3383 (public fax; no confidential information, please) 
> On 1/13/2018 4:37 PM, kg4kgl at gmail.com wrote:
>> I have already restored a BC-454 and aligned it. So that is not a problem. I have sig gen, frequency counter, and scope. 
>> 
>> When I inject the 2830khz signal, where do I check to see if the IF is picking it up?
>> 
>> Tnx,
>> 
>> Robert 
>> KG4KGL 
>> 
>> 
>> On Jan 13, 2018, at 19:26, Robert Eleazer <releazer at earthlink.net> wrote:
>> 
>>> If you hear some static but there is no change of any kind in the sound as you tune the receiver then the most likely problem is the LO.  
>>>  
>>> Aside from the obvious possibilities, be sure to check the connections to the coils under the tuning caps.  The fact that they are removable by unplugging them makes them vulnerable to the creation of cold solder joints on the chassis.  
>>>  
>>> The first thing to do would be to try putting a 2830 KHZ signal near the chassis to see if the IF picks it up.  If you don't have a suitable signal generator a cruder approach would be to take the cover off the tuning cap and carefully touch each of the connections to the tuning cap.
>>>  
>>> Good luck!
>>> 
>>> Wayne
>>> WB5WSV       
>>> 
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