[Boatanchors] HP 606 vs. 608

[Don Buska]

I understand our love for the BA's, but for me I want my test gear to be 
the "standard" in my lab.  Since the early part of this decade (after 
the DOT COM bust) newer used test instruments have really taken a big 
price hit.  With our latest economic problems this has only added to the 
amount of equipment out there at very reasonable prices.   It may be 
time to move out that 1950/60's test gears and buy some 1980's stuff.

In my case I bought an HP 8656A Signal Generator off eBay a couple of 
years back for around $300.  What it gives me is a modern synthesized 
generator that does 100kHz (see below) to 990MHz with internal AM/FM 
modulation.  Using the internal frequency standard I only experienced 
about a 1kc error max across the whole frequency spectrum.  Also, even 
though it is rated to have a lower frequency limit of 100kc it will 
accept lower frequencies entry.  I just aligned my SX-115 50kc IF using 
it and the frequency and output levels were spot on.  I used the HP 
8656A and selected external AM modulation supplied by the output of my 
HP 3325A function generator sweeping from 10Hz to 10KHz,  and then 
monitoring the IF output on an Advantest TR4171 spectrum analyzer (the 
only SA I know of that also has a Hi-Z input channel).  Immediately you 
can see what a difference it makes to fine tune IF alignments to get 
symmetrical sidebands on each side of the carrier.  I quickly found out 
that peaking the IF's for the carrier frequency won't do that.  Actually 
I quickly discovered my cause of a noticeable difference between my 
signal levels under AM-USB and AM-LSB on my SX-115.  I would have been 
head-scratching for days if all I had was an old RF generator and VTVM.  
This is a perfect setup for performing stager tuning of IF's if that is 
necessary aka HQ-170-180's.

Bottom line is many of us are willing to invest thousands in our 
stations, but then only a couple hundred, if that much, in test gear.  
Good modern RF generators can be had for well under $500 if you look for 
them.  Sweeping audio generators for much less and good spectrum 
analyzers for a bit more.  Also, another excellent signal generator is a 
transceiver.  My older Icom IC-745 has a transverter output which simply 
operates the rig minus the final amplifier.  The RF output control still 
works so I can generate an RF signal from 1.5MHz through 30MHz at a 
level up to 50mW.  I think IC-745's sell for around $300 these days.   A 
good signal generator that can also make QSO's, hi.  Plenty of the 
high-end solid-state function generators, with sweep, will go to 20MHz 
and are great for IF alignment too.  Don't go to the surplus equipment 
houses, keep your eyes open on eBay.

BTW, I gave my two 608C's away a couple of years back.  I'm glad I don't 
have to fool with those anymore.  I'm not getting any younger and if I'm 
going to pull a muscle it will be on an BA transmitter and not my test gear.

73 es take what you want and leave the rest.

Don N9OO