| F6BGV |
Rating:      |
2010-02-02 | |
| BETTER AUDIO |
Time Owned: more than 12 months. |
I own a SP-600 since a very long time.
I replaced all caps, except electrolytic and mica.
I thought it was better to install an audio section more in accordance with the quality of this famous former receiver, which will permit to get a very good sound !
I removed audio output transformer (T 7)and I replaced by another 6V6, with a new push-pull transformer (8000 CT/8) under the frame.
Then, I connected again V16A in preamplifier (Rk = 1k and Rp = 47k), straight connected to V16B as "phase-splitter" (Rk = Rp = 47k), and the two 6V6 in push-pull (Rk = 220/2W + 47 µF/63V), and a negative feed-back (Rfb = 3,3k from 8 ohms).
- HT on plate 6V6's = from C161B
- HT on screen 6V6's = from C161C
- HT on V16B = from C161C
- HT on V16A = from V18
Like this, I got a very good listening quality of the broadcasts...
Best 73's |
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| KB8QEN |
Rating:      |
2009-09-25 | |
| WORLD Class Quality |
Time Owned: more than 12 months. |
Actually this is a very well made receiver. The only real component shotcoming is the Black Beauty caps that were, at the time thought to be excellent parts. Then again that was nearly SIXTY YEARS AGO ! Of course that IS a LONG time and by the hindsight of the inexperienced it may give cause for mis-judgement of this fine receiver. The same caps were thought at that time to be a huge improvement over paper caps and were used in many high quality radios. Even the highly regarded R-390A employed them. By now re-capping is pretty much normal maintenance and this receiver will reward it's owner with brilliant performance if they are endowed with the proper disciplines to bring it out.
Of course over a period of nearly SIXTY YEARS some of these fine old receivers may have been stored for extended periods in less than optimum environments . High heats in attics and dank damp basements in the Great White Northern reaches can take a toll on even the very best gear, causing corrsion on metallic bits and insulation breakdown. Not a problem for the real technician but it may magnify the shortcomings of the less capable.If you are a bit anal about such things, consider one of the "tropicized" versions. They were specially treated and coated to minmize the ravages of enviromental extremes . They are the ones with the yellowish coating on the chassis components.
This is a very stable, sensitive receiver and stood up with the best of it's day. The audio is quite good and for MW DXing it blows away most modern receivers no matter where they were made.Of course technology has made some leaps since then but this radio is still playing today, many of them without ANY real major repairs if at all. It's performance makes it still a viable tool for day to day use on the MW to HF spectrum. Don't get to carried away with all the "JX" jargon . They are all quite gosd regardless the suffix.
A tribute to the designers and skilled assemblers of it's time . |
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| VE3PRI |
Rating:   |
2009-07-26 | |
| Poor Construction |
Time Owned: 0 to 3 months. |
| Came into possession of SP-600 J recently and discovered if this rig works its great, but the one I got had many bad caps and resistors, also found 3.5mhz oscillator had been modified and not working, and then when the radio was all together discovered a new fault cables to audio pot disintegrating, another big job here. Like I said its a great radio if it works, but overall it suffers from poor design mechanically for service procedures and poor quality caps and audio cable, not to mention the slug screw setup in the tuning turret. Surprised this radio is as valuable as it is because of these faults. If you have to do a restoration of this radio get ready for a lot of grief, and be careful to check it out thoroughly before buying one. |
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| W0OGH |
Rating:     |
2008-06-08 | |
| Good looking radio |
Time Owned: more than 12 months. |
| I currently own a -17 version of this radio. the audio transformer is shot and replacements are like hen's teeth. I liked the SX-28 for an unparalleled Classic radio in appearance. The Sp-600 here comes in a close 2nd though. Really attractive but the usual complaints exist. Where am i is the big one. However i have certain SWBC stations and ham AM spots that i operate on so i know where they are on the dial. Love the smooth tuning and fast movement across the spectrum. Not tried it on 6 meters yet but everything else works on the radio. Need to get the Audio tranny replaced, will use a 51J/R-388 collins audio transformer for that. Not worried about the AF power requirements as i'm not driving any "line" equipment anyway. And the Collins audio transformer will certainly handle all the audio i can take. Really do like this receiver. Big knobs, classic look. |
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| K9EUI |
Rating:     |
2007-12-08 | |
| Great band cruiser |
Time Owned: more than 12 months. |
I sadly had to get rid of my SP-600 (I think it was a JX-13). But I needed the room. It was probably the most stable vintage receiver I ever owned (except for perhaps the Drake 2-B). I called it my band cruiser since one could tune a wide range quickly - but this was also a disadvantage. It would have been nice if the number of band were increased to give each one more bandspread. The audio response could have been better but for casual listening it was OK.
AS I have done on other vintage receivers, I replaced one stage in it (I think it was an IF output cathode follower) with a 6BE6 as a product detector. This allowed much improved CW/SSB operation and s-meter use without having to reduce the RF gain. I'd love to find another one of these.
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| KB1OKL |
Rating:      |
2007-02-21 | |
| Excellent receiver |
Time Owned: more than 12 months. |
I bought a JX-26 last year which needed a lot of work, shipped it and got it restored by Philip Atchley KO6BB who did an excellent job (said it was his last boatanchor restoration, something about his back, hi!). I find the band scales to be right on, no need to use logging scales on mine, properly restored these things are very accurate, selective and sensitive. I use it for mainly BCB DXing and it sometimes beats my R-390A which has also been restored by an expert. It's a delight to tune with it's big dial and the crystal filter and phasing controls on mine gets rid of almost all hets. The audio is very clear on mine, am able to "hear" signals I wouldn't normally be able to understand on most other radios. I can for example copy 1521 Saudi Arabia next to WWKB NY on 1520 with it which really booms in here sometimes. I can also listen to SSB with it although the 390A is better at that for a non-SSB radio. If you get a properly running SP-600 there isn't much that will beat it and nothing that will do it with such style.
I heartily recommend them. I would buy another. I own an R-390A, an HRO-60, an HQ-180 and a SX-28A among other anchors, all are nice in their own way and are comparable in their own way. |
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| KQ6IG |
Rating:      |
2006-08-21 | |
| Nice Performer |
Time Owned: more than 12 months. |
I received my SP-600JX-17 after it had been in storage for 20 years. I brought it up on a variac, and to my surprise it worked like new! The receiver is sensitive, and selective. It also has "battleship" construction that screams quality. Mechanical and elecrical construction are both fantastic.
On the down side, the audio response lacks a low end, and the frequency resolution is poor, requiring one to make use of the logging scale. Mine is also beginning to "frequency hop", suggesting a failing silver mica cap in the turret. Not bad considering it has all original 1953 parts! Despite all this, it is still my primary AM/CW receiver.
I originally bought mine with the intention of cleaning it up, and using it for trading material. However, I'm so impressed with it that I think it will be a keeper. If you can pick one up for 0-$300, I'd say go for it!
73
Omar, KQ6IG |
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| W8ZNX |
Rating:    |
2006-02-02 | |
| swl am receiver |
Time Owned: more than 12 months. |
wanted a SP 600 since kid swl,
have owned a few earler Super Pro receivers
enjoy using old tube receivers
have owned some of the best and some of the
worst
got a SP-600JX few years ago,
fully restored stock
it is one of the very best swl receivers,
ive ever used
on am short wave broadcast it's great
am mediumwave broadcast it's even better
for amateur use it is a dog
did not expect it to be any good on ssb
so will take no points away for that
was going to use it on cw and am
on cw it's a pile
move the rf gain up and down
hear the beat note change
xtal filter dsnt do much
am use she is fb till any qrm comes along
strong ssb signal 9kc down band
will make life miserable
the SP 600 JX
is THE receiver
that disappointed me the most
may be my expectations were too high
traded the super pro for a NC 183D
glad I did
Mac w8znx
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| WB6NVH |
Rating:     |
2004-03-20 | |
| Wonderful HF SWL Receiver |
Time Owned: more than 12 months. |
| The SP-600 is wonderful for SWL use once you get used to the dial design which prevents you from knowing where you are with any accuracy (unless you write it down from the logging scale.) The audio is wonderful and the sensitivity is very good. Replacing the black plastic capacitors is a huge undertaking as others have mentioned. Having coverage up through 6 meters is very handy when the sunspots cooperate. There is apparently an issue with insulation breakdown on some production runs of the power transformer. The crystal phasing feature leaves something to be desired and the bandwidth options are not optimum for communications use. For the serious communications receiver collector, the SP-600 is a must-have and the price they fetch won't break the bank. If dial accuracy were better, I would rate this receiver a "5". |
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| WA3VJB |
Rating:     |
2003-08-22 | |
| NICE receiver !!! |
Time Owned: 0 to 3 months. |
This receiver comes closest to the venerable R-390 for performance listening to AM on the shortwave ham bands.
The SP600 and the R-390 share the qualities of receive bandwidth defined by gentle LC passband circuitry, rather than the harsh square-wave design with the mechanical filters of the R-390A.
Of course, mechanical filters are ideal for congested band conditions and being able to slice away interference using a strategy of slightly off-center tuning.
But, when conditions allow improved reception, there's nothing quite like being able to select among the 8 or 13Kc receive positions on the SP-600.
I happen to have a JX-17, late production, which did not include the failure prone capacitors known as "black beauties."
I have substituted this JX-17 for a Technical Materiels Corp. GPR-90, which I did not enjoy using because of its limited bandwidth versatility. The GPR-90, while a much prettier receiver with its symmetrical dials for bandwidth and main tuning, has only one real choice for the reception of AM fone, that of a 10Kc, LC defined bandwidth.
Surprisingly, the GPR-90 holds a higher price in the marketplace, perhaps because there are fewer examples out there compared to the SP-600.
The SP-600 is now at about the same market price as the R-390A, given examples in similar condition.
Paul/VJB
Annapolis
www.amfone.net
www.amwindow.org
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