Collins 390A vs rest of the world

[iw5ci]

In my research for the best AM receiver both for BC and for ham use, i have put in my shack some nice equipment like
Hammarlund Superpro, Hammarlund SP-600, Racal RA-17L, Siemens E309, Hammarlund 180A as general coverage and Drake B line Drake 2B, Geloso G-209
National NC-303 and  others for ham band only reception, but NEVER a COLLINS.
Maybe i have some kind of reverential scare with Collins radio as the prices here in Italy are very high (even in USA i see).
Now i have the possibility if buying a Collins 390A and my question is.... is there something really better in this radio that worths the price (and weight) of this equipment or i can live happily without this BA in my shack?

[W7TFO]

It (the R390A) is one of the legendary radios, indeed.  It deserves the praise as well. 

However, the "A" model varies from the R390 in that is has mechanical filters and a bit less robust audio amp design.

They can be made too sing nicely, but it involves some internal reworking. 

The R390 sounds better for AM out of the box, as it were.

[w3jn]

Just a note - I moved this topic from the Handbook section (which is for completed articles) to the Tech forum where it will get more exposure.

To answer your question, the '390's stability, resetability, frequency readout, and selectivity are all several steps above the receivers you have.  There's a lot to read about the R-390 and 390A on the net.   Armed with that knowledge, only you can decide whether to take the plunge or not 

[The Slab Bacon]

just for what it is worth, I use a slightly modified 390A as the benchmark that I judge all other receivers by. I have had 9 of them over the years.

                                                         The Slab Bacon

[K5UJ]

I have never owned a R390 or R390A, but I know they are extremely popular receivers.   The only thing about them that gives me pause is the mechanicals, all the gears and cams.  Do you know Lino Esposito?  He is a Collins collector and if you contact him he may be able to discuss the R390A with you, although I do not think he owns one, he appears to be very knowledgeable about Collins.  He is a short wave listener who  was profiled in the Collins Collectors Association Signal magazine last year.  http://www.linoesposito.it/index.php  Lino is SWL number IL-3152/Ge.

Another ham mentioned in the same issue of the Signal who collects Collins is Lino (maybe you have to be named Lino to collect Collins in Europe!) Scannapieco, DJ0CL in Bonn.  Maybe you can contact him to ask more about the R390A.  

73

Rob

[KM1H]

While the 390A is often used as the standard of comparison it is not an easy radio to use for general band scanning or SWL unless you enjoy lots of wrist exercise.

It was designed primarily as a point to point receiver for AM, CW and RTTY and left on one frequency for long periods. Others were used by the CIA and others for signal intercept but Id hate to be stuck in front of one for a day of tuning. Without a product detector it is not very good on SSB plus the AGC is far from ideal.

Ive had one for over 25 years and it is now used very little. The preference here for general coverage and a few for AM ham use is a HQ-180, 51J4 with mods, HRO-60, and HRO-500 with LF-10. A SX-28, NC-240D, HQ-129X/HQ-140X (great for BCB), NC-183D, HRO-50, SX-73 also get their turns to perform. A National NBS-1 which is a very low production NC-183 variant with 3 IF's and variable IF selectivity is another workhorse; it apparently was a substitute for the SP-400 when it went out of production. W3JN will be playing with his soon . A SP-400 is awaiting restoration.

The ham band only radios here are 75A2, 75A3, 75A4 (owned since 1965 and highly modified), SX-101A, SX-115.

Carl
KM1H

[WQ9E]

Carl makes an excellent point about the design intent of the R-390A and it is definitely not a band cruiser.  The R-390A was the first piece of Collins gear I bought.  The construction and performance of the R-390A is impressive and I used mine a lot when I first got it several years ago but it has been a couple of months since I have used it.  Mine is mounted in a rack with an Eldico SSB converter and the last time I had this on was when I made a couple of contacts with my Eldico SSB-100mil. 

A somewhat lighter, more easily shippable variant is the R-392.  Like the earlier R-390 it uses LC filtering and the tuning touch is a little lighter.  But the 28 volt tubes (heater and plate) do not provide quite the performance of the full blown 390 receiver.  I had my 392 on over the weekend and noticed it has a microphonic tube so it needs to come out of the case for repair.

Bottom line is that the R-390A is the perfect tool for its specific job and it is a fine receiver.  There is no perfect overall and for smooth tuning feel the SP-600 and Racal RA-17 are tough to beat.  But the calibration accuracy of the 390A is superb and the innards are a marvel.  The slug and rack design appears like the great grandson of the inventor of the cuckoo clock spent a summer internship with Isky racing cams before designing the mechanism-and he did a great job!

[The Slab Bacon]

<snip> Do you know Lino Esposito? <snip>

hmmmmm.................... I wonder if he is a relative of mine? ? ?  

[ke7trp]

I ran ham style tube recievers for years. I was content.  I then stepped up to a Collins R390A.  I was disapointed.  The audio is horrible.  You must run external audio through the diode load on the back.  Otherwise, You will be disapointed.

R390As also pick up a 50Kw disney station in my town.  Other recievers do not.

I set it aside and then picked up an Sp600 JX12. This reciever is clearly my favorite.  I changed the coupling caps for the HiFI audio mod. The sound is wonderfull. Its stable and really hears stations that the other recievers simply wont hear.

I recently restored an R390.  The regular model. This was to me is better then the A.  I use it for AM and I like the sound. It is stable and has OK sound.  Not Sp600 good.. But ok.

I have compared them side by side for 2 weeks now. The R390 and the SP600.  I still prefer the Sp600.  I can hear all stations on both. But in the end, The audio is more pleasing out of the 600.  I added an AADE digital display to the 600. 

Recievers are like women. You just know when you find the one that you like. For me, Thats the Sp600.

[The Slab Bacon]

Just for what it is worth, a stock 390A does leave a little something to be desired.
In mine I have decreased the size of the plate dropping resistor for the bfo and increased the size of the coupling capacitor. Also increased the size of the slow time constant capacitor. 3 component changes and it really does ok-fine on ssb WITHOUT a product detector and without having to back the Rf gain down on anything but the absolutely strongest ssb signals (needle pinners).

Change the local output tube from a 6AK6 to a 6AQ5 or 6BQ5, fatten up the audio coupling caps and change the local outpoot transformer to anything more hifi oreiented, wrap some simple feedback around it and it gives the audio a whole new personality. (and still be able to use the line output to drive a RTTY decoder or a TNC)
                                             
Not to say the least is to give it a good total alignment and grease job.

Mine has not been out of the rack for about 20 years!!

If I had to get rid of all but 2 of my receivers (I have 18 at present) it would be a tough choice, but I would probably keep the '390A and the SX-28 forever.

                                                    The Slab Bacon

[SM6OID]

Hej !

I have both a SP-600 and a R-390A, I like both of them. Depending on what my purpose with the listening is, I choose either the SP-600 or R-390A.
The SP is superb for band cruising, smooth and nice tuning, if I searching a limited frequency area then the R-390A may be fired up.

I'm not sure that I can answer the question "if one can live happily without a R-390A"...   

[iw5ci]

Well. i like to cruise over bands and for that i like very much the SP-600 (mine is a nice JX-29)
i have taken audio from diode output and the audio quality is very good. For ham band cruising i like very much National NC-303 and Hallicrafters SX-115 so maybe i can stay a little more without a 390.

[WA3VJB]

Yes, I have a JX21 and used it for six months without turning on the R390A right below it.  There's something very seductive about that flywheel tuning.  I have to say, like the 390(A), it still provided lots of wrist exercise moving frequency from 80M to 40M, since it's at opposite ends of the same band choice.

When and if you come back to the 390 or 390A consideration, please know the two receivers are very, very different between themselves. 

The 390, whose selectivity is defined by LC circuitry rather than mechanical filters, more closely resembles the sound of an SP600.

The 390A is a more practical receiver for use during times of high band congestion, since the rolloff of the mechanical filters is handy in rejecting off-side interference.  But the sound quality includes a certain shaping effect as a result.

As nicknames, you will be clearer if you keep the "A" intact and don't abbreviate it to "390" unless you actually mean the older sister.

All three receivers sound best when using the "diode" output into a bridging amplifier.

Well. i like to cruise over bands and for that i like very much the SP-600 (mine is a nice JX-29)
i have taken audio from diode output and the audio quality is very good. For ham band cruising i like very much National NC-303 and Hallicrafters SX-115 so maybe i can stay a little more without a 390.

[ke7trp]

If your Sp600 has the Xtal control.  You can order up Xtals from AF4k.  I put, popular 40,75, 160 freqs in mine. Now its just a flip of the switch to check the bands

C

[w3jn]

DOn't you have to adjust the dial anyway to tune the front end and mixer?