[Elecraft] OT: Oscilloscopes

[Jim Wiley]

Howard et al -


Another option for you to consider:   The Tek 7603 series plug-in scopes 
are substantially  more versatile than a 465 or 475 series unit.  
Depending on the prices you are seeing for the 465/475,  it is quite 
possible that you could find a 7603 at lower cost.  Also, you can use 2 
dual-channel vertical amplifiers (a pair of  7A26 units are a good 
choice) and a dual time base sweep generator (the 7B53A is the best 
choice here) and have a true 4-channel 100 MHz scope.   100 MHz is fast 
enough for most "normal" logic stuff, and the scope will still give 
useful response well past 2 meters for checking radios and such.   You 
will also need a good set of probes.  The best option overall is a set 
of 10X probes that have 2 meter (6.5 foot) cables. Unless you are 
working on modern (very fast) logic circuits, a 100 MHz analog scope 
will do virtually anything you might need. It certainly is good enough 
for the "usual" TTL and CMOS logic found in most ham gear.    I


There is also the storage tube version, the 7623A.  It has a storage 
type CRT, very useful for slow sweep work, such as when using one of the 
spectrum analyzer modules (I have one for that purpose).   The 7623A 
tends to be more expensive, typicially, about twice what "plain" 7603 
units go for.   It also has a smaller display area  (approx. 7 X 9 cm)  
as opposed to the 7603 (approx. 10 X 12 cm), which is due to the storage 
tube.   The 7623A has the same 100 mHz performance as the 7603.


Disadvantages:  the 7603 types are physically larger that the 465 
series.  Also bit heavier, but still easily transportable.


Advantages:   MUCH larger screen size.  Good for old timers like me.     
But, here's the best part:  Plug-ins!  Available units include a very 
broad selection of vertical amplifier and and horizontal time base 
units, plus a set of very competent spectrum analyzers (the 7L13, 
covering 1 KHz to 1800 MHz  is most useful for hams), a DVM unit,  and 
even "blank" modules that you can build your own custom stuff into.  
Should repair ever be necessary, the 7603 is much easier to service than 
the 465 series.


I have seen mainframes on Ebay in the $500 range for guaranteed good 
working condition,  and vertical and horizontal plug-in units from $15 
to $75, depending on model and condition.  I have also seen much lower 
(and higher) prices at hamfests.   The last 7603 I purchased (I now have 
3) was $400 for the base unit, and  $30 each for 3 plug-in units.


I would stay away from the Tex 5000 series.  They are good, but the 7000 
series offer substantially better performance and the selection of 
option modules is much better.  At surplus prices, the price difference 
is usually not enough to make the savings worthwhile. .


You will never be sorry that you purchased a Tek scope.   There are 
indeed some fine instruments from other manufacturers, but Tek is the 
"Gold Standard" when it comes to scopes.    My personal test bench is 
almost all Hewlett-Packard,  except for the scopes.   IMHO, a clean used 
Tek is to be preferred over a new anything else.
 

Just my 2 cents worth. 


- Jim, KL7CC


Howard W. Ashcraft wrote:

I currently considering replacing my existing oscilloscope with an older 
Tek model.

<snip>