Amps
[Top] [All Lists]

[AMPS] More SB-220 Comments

To: <amps@contesting.com>
Subject: [AMPS] More SB-220 Comments
From: measures@vc.net (Rich Measures)
Date: Mon, 14 Jul 97 08:19:45 -0700
>
>On Fri, 11 Jul 97 17:40:42 -0700 Rich Measures <measures@vc.net> writes:
>>snip...
>>> The correct choke rating is 100ma 
>>
>>Not acording to the Heath parts list.  #27ga. wire in a 100mA choke?  
>
>The Heath chokes are #30 wire Rich, at least all the ones I have checked
>here. 
As I recall, #30 copper wire has a fusing current rating of around 8A.

>I just dont like that resistor idea since it adds all those extra 1000pf
>caps into the equation. 

So check it with a dipmeter.  The difference in grid resonant frequency 
between the original 600pF and 1600PF is quite small.  

>If you want a resistor, why not just wind a 1 mh
>choke ... ...?

Because chokes have pesky resonances that resistors do not have, AND it 
doesn't take 8A of grid-current to blow a 20 to 39 ohm 1/2w carbon film 
resistor.  .

>Guess I'll stick with what I'm comfortable with until I can be convinced
>otherwise. For sure, I will not directly ground the grids without some
>form of a fuse link or other protection. I have fixed too many AL-82,
>AL-80A, SB-1000 type amps to want to go that route.

Amen to that, Carl.
Rich---

R. L. Measures, 805-386-3734, AG6K   


--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm

<Prev in Thread] Current Thread [Next in Thread>