[Boatanchors] Boatanchor purchase suggestions

[Al Klase]

Chris Bower wrote:
> ....General coverage receiver to 30 MHz or thereabouts. (I mostly listen to the
> ham bands, but sometimes general SW broadcasts.)
> Must be ALL tube (God, I love radios that glow in the dark!)
> Sensitivity and audio quality would be my primary requirements.
> I have no brand preference at the moment.....

Chris and The Group,

First a couple of questions;

How important is frequency accuracy?  Collins changed 
everything in the late 1940's with the introduction of the 
51J and later R-390's.  "If you want to find them, use a 
Collins.  If you want to listen to them use a Super-Pro or 
AR-88."

How important is audio fidelity?  Especially, frequency 
response above 3 KHz and below 200Hz.  I.e., do you listen 
to music or want to enjoy the "East-Coast Sound" on ham-band AM.

How important is good SSB performance?

It's difficult to name a receiver that has it all.

R-390: Undoubtedly one of the best communications receivers 
ever.  But:  Not a "Band Cruiser."  Frequency change gets 
tiresome.  Variable IF selectivity is a great feature, but 
for AM you have two filters:  4HKz - Almost Too narrow.  8 
KHz - Too wide.  It lets the 5KHz hets on short-wave 
broadcast come right through. (However, the 3KHz audio 
filter on the "Non-A" helps here.) Not really designed for 
SSB, but there are some simple mods that help a lot.  Audio 
needs work if you're seeking fidelity.

Hammarlund HQ-180:  Was designed to handle SSB as well as AM 
and CW.  Tunable first local oscillator means it falls short 
of the Collins for frequency accuracy and stability. 
Limited selection on IF bandwidths.

Recently I've been playing with band-cruisers with good 
audio fidelity.  Here's what I'd suggest.  These all have 
tunable first LO's so you're sacrificing stability and 
accuracy somewhat.

Hammarlund Super-Pro: The SP-10 - SP-100 - SP-200 series 
have great audio in stock form and were designed as 
professional receivers.  External power supply is a minor 
annoyance.  SP-400 is very similar, but I find it physically 
revolting.

SP-600:  More modern and extravagently constructed.  Low 
frequency audio was deliberately rolled off. However, I 
recently posted easy mods on my website that fix this.  (See 
the Communications Receiver section.)

RCA AR-88:  I feel this was the BEST RECEIVER ON THE PLANET 
before the introduction of the 51J.  Variable IF bandwidth, 
Excellent audio. Don't be fooled by the single-ended 6K6. 
It sits in the middle of a well designed feedback loop. 
Excellent engineering overall.


My two cents,
Al


-- 
Al Klase - N3FRQ
skywaves@bw.webex.net
Flemington, NJ 08822
Web Page:  http://www.webex.net/~skywaves/home.htm