[Hallicrafters] 6SC7 tubes new or used wanted

[Richard Knoppow]

     Beware that this is a very early article. Metal tubes were 
introduced about 1934 although I don't remember the exact year. Early 
metal tubes had some problems with their seals so were sometimes a 
little gassy. The problem was solved before long. There are small 
differences in interelectrode capacitances. In some cases glass tubes 
continued to be preferred over metal ones. Metal tubes were claimed to 
have perfect shielding but that is not always the case. There are 
differences in size, for instance, I can not use a glass 6SA7 in my 
S-40A because it is just slightly too large to clear the stop pin on the 
band spread capacitor. That my not be true for other receivers of this 
model.
     BTW, a complete collection of "Radio Craft" is available at
http://americanradiohistory.com/
along with many other early radio and broadcast magazines.
http://americanradiohistory.com/Radio_Craft_Master_Page_Guide.htm

On 9/15/2017 4:53 AM, Ray Keefe wrote:
> I have often wondered about the difference between metal and glass 
> versions.
> 
> What I have found is if the tube was made in both metal and glass the 
> metal version would be called a 6SC7 and the glass version would be a 
> 6SC7 GT (Glass Tube).
> 
> Here's a link to an article from 1935 about metal vs glass tubes.
> http://www.rfcafe.com/references/radio-craft/metal-vs-glass-radio-tubes-radio-craft-october-1935.htm 
> 
> 
> 
> 
> On 9/14/2017 9:40 PM, Richard Knoppow wrote:
>> Well, that's the definitive answer. A lot of tubes were made both ways.
>>
>> On 9/14/2017 6:35 PM, Jacques Fortin wrote:
>>> Hi all,
>>> I have some 6SC7 GT made of glass.
>>> Some NOS are on sale at:
>>> http://dbtubes.com/en/search?controller=search&orderby=position&orderway=des 
>>>
>>> c&search_query=6sc7&submit_search=
>>> I'm not related to this site in any way but prices and service are good.
>>>
>>> 73, Jacques, VE2JFE
>>
>>
> 

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL