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Author Topic: Duplicating Collins Radios ?  (Read 4975 times)
SWMAN
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« on: January 22, 2012, 08:16:34 AM »

 I was just real curious about something. I know that the old Collins radios like the R-390, R-391 and R-392 were some of the best radios ever made.But they were produced in the 1950's and 60's and long time ago. Some say these radios can never be duplicated! Why ?
With technology being so great in electronics today, why can't we make a similar receiver as good as a Collins? Even with a big price on a good receiver they say it can't be done. Just curious to why.
73 Jim W5JJG
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N4NYY
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« Reply #1 on: January 22, 2012, 08:45:29 AM »

I saw the mechanism on the R-390. And as with the rest of the radio, the production costs would just be too exorbitant. Remember, ham and SWL is a clique. It is not a Samsung LCD TV where you could lower production costs with mass quantities. Most of the radio would have to be assembled manually, and that would outrageous today. Back in the day, this production was the norm. Today, it would essentially be custom.
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AC5UP
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« Reply #2 on: January 22, 2012, 08:51:34 AM »

Pop the lid on an R-390 or -390A and you can see where the money went... Incredible attention to detail with everything trimmed, dressed and even the holes line up. The machine work is a delight for the eye and with rare exception the parts used were among the best available at the time. Electrically both radios were over-built in terms of front end filtering and the number of tuned elements in the IF strip. Expensive design, but with nicely distributed selectivity and gain the end result was a very low noise floor, near-perfect bandpass characteristics, few if any images (birdies) and a permeability tuned VFO that didn't QSY unless you told it to.

Flash forward to today.

If you've torn down hard drives, printers or VCR's over the past 20 years you know how VCR's in particular went from moderately priced mechanical marvels of 25 years ago to a near empty box of 10 years ago that did more, cost less, and didn't break. Let's apply the same idea to a modern day JA-390..........

Can we build a multi-stage IF strip using miniature parts and chips that has the same gain and bandpass characteristics as the original R-390? Sure can........ Permeability tuned front end? That's maybe 2-3 times more complicated than a VHS tape loading mechanism, so, yeah, can do. Zero drift miniature PTO? Yuh. Power supply? Check. Audio? Duh. Attractive box with analogue dials & knobs....... Hell Yes, but there's the catch.

As soon as you think about building a processor or synthesizer into a JA-390 you now have PLL and clock noise from the square wave pulses running around the digital side of the rig. Can that be filtered away from the analog side? Well, yeah, but what do you think YaesuKencomWood is doing now? In terms of specs the newest gear runs rings around the old Collins / Drake / TMC et al gear from the day and has for close to 20 years. But in terms of perceived quality and the joy of using it, the old mil and high-end ham gear still has a loyal following.

In any case, if you want the characteristics of a pure analog rig you'll need to forget about digital displays, DSP, memory channels, direct frequency entry, etc. I have a hunch you couldn't sell a radio like that today in sufficient quantities to make it pay because the narrow market segment that wants an R-390 will find an R-390. Nothing else will do, and any rumors to the contrary are heresy

The rest of us? Love that plug and play and not having to peak the preselector with every QSY...
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M0HCN
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« Reply #3 on: January 22, 2012, 09:04:49 AM »

It can be done, but the real issue is that I think people were comparing against other contemporary sets, and for most uses the variation in the quality of modern receivers is far smaller then it was back then, thus the differences are smaller.

I also think there is a little bit of 'rose tinted spectacles' viewing going on.

You get similar things said about the old Drake sets, and while they can be updated fairly easily to be at least competitive. Stock? well lets just say things have moved on.  

Also remember that the S line were not exactly cheap by any means, let alone something like an R390 which was a $2,500 proposition back in 1951 (Equals ~$20K in 2011)!

For that these days, you could buy a very nice set from Rhode and Schwartz or similar, forget the stuff marketed as amateur service.
The real issue is that nobody is prepared to pay for really state of the art performance (because almost nobody needs it), so if you do want to play state of the art in HF radio you pretty much need to build it yourself these days or look outside the amateur market.

73, Dan.
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G3RZP
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« Reply #4 on: January 22, 2012, 09:11:58 AM »

In terms of IMD, the R390 is not that good. On the other hand, the amount of front end filtering means that a lower than optimum intercept point (by today's standards) allows  the receiver to 'get away' with it, to a great extent.

But the expense of doing it today......the mind boggles!
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K8AXW
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« Reply #5 on: January 22, 2012, 09:22:44 AM »

CHE: (Military - Europe 1955)  We were one of the very first units to receive the R-390A.  We were told that they cost $2500.00, which was more than double the price of the other receivers we were using at that time.  I had the opportunity to look inside and was totally blown away by the construction.  Absolutely a work of art. 

As you also pointed out, today's price for the same thing would be around $20KBs!  However, present day equipment will outperform the R-390A and cost much less. 

I no longer have any idea what a mil-spec receiver (one designed to take a beating like the R-390A) would even look like.  It isn't likely the average ham receiver these days would stand up to military use for very long.
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M0HCN
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« Reply #6 on: January 22, 2012, 09:48:16 AM »

I no longer have any idea what a mil-spec receiver (one designed to take a beating like the R-390A) would even look like. 
Thales TMR5100 might well be reasonably typical for a fixed install or a communications truck or such.
Quote
It isn't likely the average ham receiver these days would stand up to military use for very long.
True, but would the average ham receiver from back then have done much better, the S line was high end kit, never mind the R390-A.

73, Dan.
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G3RZP
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« Reply #7 on: January 22, 2012, 10:44:58 AM »

I think the S line was later than the R390 and its variants
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KATEKEBO
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« Reply #8 on: January 22, 2012, 10:54:45 AM »

Why try to reproduce something if modern technology is infinitely superior.  Take a modern receiver like a Rohde-Schwarz and dances circles around an old Collins. What happens is that average age of today's ham radio operator is 70+, and there is a lot of nostalgia in the hobby.
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KK4GER
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« Reply #9 on: January 22, 2012, 11:40:03 AM »

Why try to reproduce something if modern technology is infinitely superior.  Take a modern receiver like a Rohde-Schwarz and dances circles around an old Collins. What happens is that average age of today's ham radio operator is 70+, and there is a lot of nostalgia in the hobby.


At 62+, I somewhat resemble that remark.  Smiley  But consider this as well, the newer radios are just about throwaway units.  They perform better, but you have to jump through hoops to repair them, usually returning them to the factory or an authorized service center.  Not so with the older units, and most of us old timers enjoy(ed) popping the covers off these rigs and poking around with a 'scope probe and the like.  Just another consideration.
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KATEKEBO
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« Reply #10 on: January 22, 2012, 01:15:37 PM »


At 62+, I somewhat resemble that remark.  Smiley  But consider this as well, the newer radios are just about throwaway units.  They perform better, but you have to jump through hoops to repair them, usually returning them to the factory or an authorized service center.  Not so with the older units, and most of us old timers enjoy(ed) popping the covers off these rigs and poking around with a 'scope probe and the like.  Just another consideration.

It depends.  The radios intended for general consumer market and amateur radio are certainly built to a different standard than old radios which were directed towards military applications.  But today's professional and military radios are extremely reliable and can take a lot of abuse.  However they are simply too expensive for the average user.  A JRC ship receiver costs >$10,000, a military-grade Rohde-Schwarz >$25,000.  This is still cheaper, in relative terms, then a Collins 60 years ago.  Even a professional-grade receiver today is cheaper than an average family car, while a Collins at $2500 was way more expensive than a car in the 1950's (around $1500).
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M0HCN
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« Reply #11 on: January 22, 2012, 01:17:51 PM »

Been known to extensively modify modern rigs as well, the techniques change (SMT), but I have more then one modern rig where the front end has been modified to output an IF that I then do my own thing with (And one where the micro went unobtainable, where I replaced the entire processor with a more modern part (and wrote the code)).

"No user serviceable parts inside" is supposed to be as a challenge, isn't it?

Cost effective? Not very, but then none of it really is.
The older rigs did tend to far more of an exposition of the sheet metalworkers art then the modern stuff.

And yea, the S line was considerably more recent then the 390A.  

Regards, Dan.
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AA4PB
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« Reply #12 on: January 22, 2012, 02:37:41 PM »

If you compare apples to apples (that is ham gear to ham gear and not military gear to ham gear) then you'll find that most high-end modern ham gear is far superior to any 1950's ham gear.

You'll also likely find that modern military grade gear is far superior to1950's military grade gear.
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N3QE
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« Reply #13 on: January 22, 2012, 02:50:28 PM »

Nobody would slavishly duplicate the 390A. Nothing wrong with the 390A for what it does... but lack of a real product detector in it is a big problem with the ham modes of the past few decades. 100kHz/turn tuning was fine back in the days of AM but doesn't cut the mustard for modern modes.

Today's downconversion ham rigs are superior on the ham bands and modes in every way except front end selectivity.

Some ham rigs have, with the right options, front end selectivity over specific bands about as good as a 390A. e.g. Yaesu VRF or Icom Digi-Sel.

I've used a fair number of modern milspec general coverage receivers (e.g. Watkins Johnson, Rohde-Schwarz) and most of them are actually pretty sucky in usability compared to a ham rig. It's not that they're bad radios, just that general coverage receivers despite stellar specs are not a good match to a well engineered purpose-built box. Most military and marine communications is channelized which simply doesn't match ham usage.
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M0HCN
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« Reply #14 on: January 22, 2012, 03:59:52 PM »

True, you got to pick the right tool for the job, and actually the major usability thing is the user interface once you get to a basically competent RF circuit.

I am far from certain that the user interfaces have improved with time recently, the buttons and menus instead of knobs feels like a step backwards to me for all but the least frequently used controls. It definitely makes for a cheaper radio, but I am not convinced it makes for a better radio.

Also I am not convinced that the move to ever smaller radios is automatically a good thing in a base station rig, dammit I like controls I can actually see and hit quickly.

A subject somewhat dear to my heart as I am working on the front panel layout for my latest set.

Regards, Dan.
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