[Elecraft] Analog meter

[Don Wilhelm]

JT,

Most of the times that an analog meter is helpful is when making peaking 
adjustments to tuned circuits, so what you really need is a meter system 
that can detect and display the amplitude of an RF waveform - the 
following are suggestions:

For a *really* fast responding 'analog meter', use an oscilloscope - the 
vertical deflection represents the voltage - the advantage of the 
oscilloscope is that it can work at low RF voltage levels as well as 
higher levels.

Many DMMs have an "analog" bar graph display that is fast responding.  
Use in conjunction with an RF Probe.  An older VTVM will suffice instead 
of the DMM, but also will likely be used with an RF Probe in most 
cases.  Note that a VOM will not work very well because it loads the RF 
probe output significantly.

An analog meter SWR meter will measure the relative level of RF at the 
transmitter ouptut - the peak is easy to see when making adjustments.  
This one is already available in many hamshacks and will suffice nicely 
as long as the transmitter is working.

A very nice meter for measuring RF directly over a wide frequency range 
and from very low levels to quite high levels can be homebrewed - see 
the article from QST June 2001 page 38 titled 'Simple RF-Power 
Measurement' by Wes Hayward W7ZOI and Bob Larkin W7PUA.  Fitted with an 
analog meter, this instrument will measure from nanowatts to a 
milliwatt, and when used with a 30 dB coupler like the Elecraft CP1, the 
range can be extended up to about 10 watts, or with the 40 dB Tap that 
is shown in the article, the range goes up to 100 watts.  A very nice 
instrument indeed, but be careful to shield the input well, this is a 
VERY sensitive meter.

73,
Don W3FPR

JT Croteau wrote:
> W3FPR and others frequently recommend good quality analog meters for
> doing several alignment procedures and for performing countless tests.
>  I'd like to get one but have no clue what to look for in this day and
> age of digital test equipment.
>
> Advice, recommendations please?
>
>