[Boatanchors] First radio

[Jim Wiley]

Preston -


Having used both radios you mentioned, here is my 2 cents worth.  I have 
owned and used both sets, although I no longer have either.  A modern 
solid-state (what heresy!) transceiver with general coverage, such as a 
Kenwood TS-570, will outperform either -  but then you don't get the 
satisfaction of the "glow factor" and the impressive appearance, both of 
which I agree have their own value.  I have three boat-anchor receivers, 
a BC-348, a Hallicrafters SX-28 and a Hallicrafters SX-71 for those very 
reasons.   I also have 3 boat-anchor transmitters, a Heath DX-20 (my 
original novice rig), a Johnson Ranger that goes with the SX-71,  and a 
Collins 32V-1 which I am restoring.  The 32V-1 will "pair up" with the 
SX-28 when I get it going.


For it's ability to easily get back to a specific frequency and the 
advantage of mechanical filters, the '390A would be a good choice. It 
has good overall sensitivity, adequate selectivity, and decent (not 
great) ability to handle front end overload.  Mechanically, it is 
incredibly complex,  difficult to align without a whole set of 
specialized tools and detailed operating manuals, and it uses some hard 
to find tubes.  Using a '390A for casual listening, particularly for 
just scanning the bands to see what is on can be an exercise in 
frustration, as it takes lots of "cranks" on the tuning knobs to move 
around the band, and there is no "flywheel" action or equivalent.


The SP-600 is a much different design.  It's analog tuning mechanism  
operates smoothly, but is difficult to  set to a specific frequency, 
although  when used in combination with an  external crystal calibrator 
having 25 or even 10 kHz markers, that is usually not that much of a 
problem.  The SP-600 does have the advantage of covering frequencies up 
to and including the 6-meter band. It has good sensitivity across it's 
entire tuning range, a great audio system, and the ability to be 
crystal-controlled on several spot frequencies (you have to purchase the 
necessary crystals).  The tuning mechanism is smooth and a pleasure to 
use, with good flywheel action, useful for rapid moves up and down the 
band. 


In general, the '600 uses commonly available tubes, and there are no 
"unobtanium" parts other than the usual difficulties that apply to older 
parts.  Things like power and audio transformers, specific RF and IF 
transformers, variable capacitors and such are sometimes difficult to 
obtain for either set, but there are enough "junkers" out there being 
"parted out" that almost anything can be found with a little looking.  .


Each set is large and heavy.  Each has a good "front-end", RF wise.  
Once warmed up, each has good frequency stability.  The '600 is 
considerably easier to maintain, particularly when considering the 
complex gear trains involved with the '390A.   If you have a '390A and 
it has PTO problems (the heart of the set) it may be difficult to find 
parts short of stripping one from another set.  The crystal filter in 
the '600 is not as good as the mechanical filter system that the '390A 
uses, but it is entirely adequate for  casual listening.    Each set  
performs adequately for SSB reception, but neither is optimized for that 
use.  There are SSB adapters for each set, but they are somewhat rare 
and hard to find. 


Since you say your primary use of the set will be for general listening, 
I would recommend the SP-600 as a much better choice for that type of 
use.  Try go get one of the later production units.  I think a 
SP-600-JX17 (I think I have that right) is about the latest available, 
although someone here may have better information.  The "X" in the model 
number indicate the set has the crystal-control option. 


The number one advantage of the '390A is in frequency settability 
without the use of external "helpers", something that is important for 
use by relatively untrained troops.   While the rest of the receiver 
offers good to excellent performance, it seems to me that the design 
philosophy of the '390A made all the rest of secondary importance.


I hope this helps, but all of this is just my opinion, based on my use 
of each set.  I am sure others will have their own ideas.  Maybe you can 
make arrangements to temporarily borrow an example of each set to help 
you decide.


- Jim, KL7CC



Preston Clark wrote:
> i am currently looking at getting my first boatanchor radio i am
> tossed between the collins 390 or the hammarlund  SP-600 i plan on
> using it it for general listening  and i need to know the antenna
> specifications for these and if one better than the other  i currently
> live in a house that i can use a outside antenna  but need the
> flexibility of maybe using a loop antenna if anyone has done that
> also any ideas of adding a transmitter of the same period  thanks
>
> Preston kf5evv
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