[Hallicrafters] Speaking of Resistors

[Charlie T, K3ICH]

I'll bet it's a typo.  He probably meant 58 k, not 58 Ohms, since he stated 
it measured "high"..

73, Chas
----- Original Message ----- 
From: "Richard Knoppow" <1oldlens1 at ix.netcom.com>
To: "Robert Sauvan" <rsauvan at beyondbb.com>; "Hallicrafters" 
<hallicrafters at mailman.qth.net>
Sent: Wednesday, June 04, 2014 8:41 PM
Subject: Re: [Hallicrafters] Speaking of Resistors


>
>
>
> -----Original Message-----
>>From: Robert Sauvan <rsauvan at beyondbb.com>
>>Sent: Jun 4, 2014 5:34 PM
>>To: Hallicrafters <hallicrafters at mailman.qth.net>
>>Subject: [Hallicrafters] Speaking of Resistors
>>
>>Hi all,
>>As you are all aware, we had a very good education in checking and
>>replacing resistors last week. I put the SX-101 back in service and am
>>finding it to be working quite well up to this point. I have now brought
>>the HX-50 onto the workbench to try to locate the chirp I have in this
>>rig. I know its not Hallicrafters, but Im sure all of you are familiar
>>with this unit. So, I started troubleshooting and decided to start
>>checking resistors after my lesson from last week. One particular
>>resistor in the K101 relay looked to be somewhat suspicious. It had a
>>kinda shiny surface and very very small bubbles or bumps on the surface
>>so I decided it must have gotten hot at one point. The manual called for
>>a 47K
>>2 watt resistor in this circuit. The bands on the resistor in the radio
>>indicated it was a 41K. When I put my meter on it, it showed about 54
>>ohms. Wow, it was way high as I was told bad resistors will show as they
>>get old and in a circuit. I picked up a new resistor today with the
>>correct spec as the manual indicated it should be. I cut the old
>>resistor out and rechecked it. It measured almost 58 ohms out of the
>>circuit so it is definitely bad. I replaced it and fired up the rig and
>>my oscilloscope shows a nice waveform. The waveform previously had been
>>a bit skewed so I dont know if that is what a chirp looks like on the
>>scope or not. I have not monitored the signal as of yet because my shack
>>is a bit far away to hear it in one of my receivers. I have ordered all
>>new electrolytics for this radio since I have the case open and plan to
>>replace them since it would be a good time. They should be here tomorrow
>>so I will replace them and put this thing back on the air and see if I
>>get any more 579"C" signal reports. Lesson well learned and executed.
>>
>>We thank you-Bob-W0YBS
>>__
>      This is very unusual.  Mostly carbon composition resistors go high in 
> value, occasionally doubling. I can't remember ever seeing one go low. 
> This one sounds like it developed a partial short.  I understand something 
> of what makes them go high but can't figure out how this happened. I 
> wonder if this is actually a low value resistor someone put in.  Check the 
> color stripes again. If the thing got seriously overheated it may have 
> affected the colors. Let us know what you find.
>
>
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