[Drake] Drake Digest, 40 meter high plate current

[Joe]

On Sat, 2011-03-19 at 14:43 -0400, FJMelick at aol.com wrote:

>  ...bad 40M, good 80M, good 40M...

Sounds like dirty switch/relay contacts. 

>I am looking to buy a used 20 mhz scope next. Any opinions?...

A typical 20MHz scope will be 3dB down at 20Mhz and have inferior
triggering capabilities.  For HF use, this is marginal and of
questionable value.  A better alternative is a 60 MHz or better scope
from Tektronix, which be more accurate for the HF frequencies and
provide more stable displays.

To get a reading on relative "sold" prices, go to an online auction site
and query completed sales for: 

"20 MHz" osci* 
and
tek* (2205*, 2213*, 2215*) 

You will see that for the most part, the average sale price for these
scopes is in the $75 to $100 range delivered, both 20 and 60MHz. 

The TEK 2213, 2213A and 2215 are 60MHz scopes with very usable
triggering capabilities, plus free manuals may be found on: 
 http://bama.edebris.com/manuals/tek/ 

There is an active support group for all Tektronix gear at: 
 http://groups.yahoo.com/group/TekScopes/   

I have found the inexpensive 60 and 100 MHz imported probes to be very
usable with these scopes. 

"ABC's of Oscilloscopes", "XYZ's of Oscilloscopes" and "ABC's of
Probes", all from Tektronix, will serve you well in understanding how
they work and how to use them. 

For a few extra bucks, you will have a piece of test equipment with
documentation, that is repairable and a joy to use. 

HTH, Joe, K9HDE