[RFI] Are nuvistors sturdier than transistors?

dgsvetan at rockwellcollins.com dgsvetan at rockwellcollins.com
Thu Aug 30 14:48:55 EDT 2007


As Jim Brown said, Nuvistors are tubes, and as such, would withstand 
certain transient events better than some solid state devices, but maybe 
not as well as "regular" tubes.  That's because of simple physics and the 
effects of spacing between different conductive elements of the tube 
realative to a fast risetime high voltage event. 

Hams might have a few Nuvistors kicking around if:

1.  They have an RCA "Nu-Vista" TV from the 1960's - they were used in the 

2.  They have certain models of Ameco VHF receiving converters (for 6m and 

3.  They have certain models of Ameco VHF pre-amplifiers

The design of the Nuvistor was well-suited for VHF and UHF applications: 
small internal elements with short leads.  RCA (and probably a few other 
TV set manufacturers) used them in TV tuners.  Ameco (and probably a few 
other manufacturers) used them in VHF converters and pre-amps.  Back in 
the late 1960's, I had an Ameco 2m pre-amp with a 6CW4 Nuvistor ahead of 
my RME VHF-152A converter for use on 2m AM in the Chicago area.  (Yes, 2m 
AM.  Even though 2m FM was already booming by the late 60's around 
Chicago, there was a fair number of AMers active until 1972 or so.)  I 
currently have a recently acquired Ameco CN-7 2m receiving converter that 
will be placed ahead of my Hammarlund HQ-110 so that I can make a working 
2m AM receive set-up to go with my Ameco TX62 6 and 2 meter transmitter. 
The CN-7 uses three (3) 6DS4 Nuvistors.

While it's a lot of fun to play with the oldies, I can tell you that 
functionally, modern solid state devices will way outperform Nuvistors as 
VHF and UHF pre-amps, primarily in the area of Noise Figure.  If you are 
concerned about the effects of lightning or precipitation static on modern 
solid state devices, there are many ways to mitigate the threat. 

73, Dale


kd4e <doc at kd4e.com> 
Sent by: rfi-bounces at contesting.com
08/30/2007 01:50 PM
Please respond to
doc at kd4e.com

RFI List <rfi at contesting.com>, tvi-rfi-emi at mailman.qth.net

[RFI] Are nuvistors sturdier than transistors?

Am I correct to believe that a nuvistor would be more
resilient versus transients from surges such as static,
nearby/indirect lightning strikes, and other emp sources?

Do nuvistors 'age' like tubes or are they pretty much
stable over time like silicon (not germanium) transistors?


Thanks! & 73, doc, KD4E
Personal: http://bibleseven.com/kd4e.html
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