SBE Console 6. Some days the bear gets you.

[nomadradio]

Had a puzzling issue with a SBE Console VI (six) radio. Made me suspect that the custom "brain" chip from 1979 that runs the channel display/selection had failed. Would be bad juju, since that part hasn't been made in four decades. But it spontaneously began to work before quitting again.

This radio got a full re-cap, courtesy of Klondike Mike's cap kit and sixty-plus solder joints.

But just now my idiot light came on.

Some days the bear gets you. And sometimes it's because you f**ked up.

I replaced every cap on the main pc board, and in the power supply.

But not on the separate "Up-Down Unit" circuit board where the brain chip resides.

Hmmmm. Idiot light's getting really bright just now.

Didn't have those caps left over from the kit.
Hmmm.

Looks like maybe I should make a list and change out those caps before passing judgement on that chip.

And if it still goes nuts, I'll be back to see if anyone has insights about the wacky "tin can" PLL module and its behavior after channel expansion. Had my suspicions about the low-pass filter between the down mixer and the PLL chip's divide-by-N input.

Came up dead short on that issue when the channel selector controls went psycho. Can't much judge what the PLL is doing until you can tell it what channel to select.

73

 

[TM86]

Had a puzzling issue with a SBE Console VI (six) radio. Made me suspect that the custom "brain" chip from 1979 that runs the channel display/selection had failed. Would be bad juju, since that part hasn't been made in four decades. But it spontaneously began to work before quitting again.

I revived a brain-dead Console V (five) with an arduino. Worst case scenario it might be possible to do the same here. Of course, the inputs and outputs are completely different, so my solution won't work for you as a drop in.

Hopefully it's just the caps.

 

[nomadradio]

Only two things needed to replace an obsolete digital controller chip with an Arduino or similar.

Specs.

Analysis/programming labor.

Okay, three things. You gotta wire it all up, too.

Makes it sound easy, until the analysis stage shows you how much programming it will take.

Traditional economics apply. If you'll only produce one copy, that will make it prohibitively expensive. Like building your own carburetor starting with a sand mold for the body.

But if you'll duplicate it fifty or a hundred times the development expense of that first unit gets split fifty or a hundred ways. Makes the per-unit design cost look a lot better.

And anybody who invests what it takes to do this will want to get that money back from that first fifty, at least.

73

 

[TM86]

Only two things needed to replace an obsolete digital controller chip with an Arduino or similar.

Specs.

Analysis/programming labor.

Okay, three things. You gotta wire it all up, too.

Makes it sound easy, until the analysis stage shows you how much programming it will take.

Traditional economics apply. If you'll only produce one copy, that will make it prohibitively expensive. Like building your own carburetor starting with a sand mold for the body.

But if you'll duplicate it fifty or a hundred times the development expense of that first unit gets split fifty or a hundred ways. Makes the per-unit design cost look a lot better.

And anybody who invests what it takes to do this will want to get that money back from that first fifty, at least.

73

And that's the difference between doing it for a shop and doing it to see if you can. I had the advantage of not caring about the time cost for reverse engineering the remains of the original and programming the new.

So if it's truly dead, let the owner know you may have someone who's willing to buy the carcass off him. At a reduced price, of course.

 

[Retro CB Guy]

Well we shall see, it's mine Nomad talks about. I've got a feeling he'll get it fixed this Friday when I venture over there with my made appointment. Thanks to both of you for the idea exchanging and banter back and forth very much!

This one is also a NOS specimen which makes it worse for me...

Retro

 

[Retro CB Guy]

I revived a brain-dead Console V (five) with an arduino. Worst case scenario it might be possible to do the same here. Of course, the inputs and outputs are completely different, so my solution won't work for you as a drop in.

Hopefully it's just the caps.

I'd like to see some pictures of this one some time please !

73's Retro

 

[Retro CB Guy]

The only thing though that puzzles me with that on my Console 6, is it is operated with buttons to go UP and Down channnels by a computer chip sooooo I don't know or understand how one would accomidate that with a DDS setup installed?

 

[TM86]

The only thing though that puzzles me with that on my Console 6, is it is operated with buttons to go UP and Down channnels by a computer chip sooooo I don't know or understand how one would accomidate that with a DDS setup installed?

Arduino is a microcontroller, it only becomes a DDS when connected to a SI5351 or similar clock generator. You could also use a RaspberryPi in place of the arduino if you prefer massive overkill.

The idea is you take the inputs you can see and try to figure out what the outputs should be, then program the controller accordingly. With the Console V it was easy, as it used pulses fed to a controller chip that in turn turned on and off the appropriate pins for the PLL programming lines and the seven segment LED displays. Another thing I got lucky on was that everything I needed to interface to was using 5 volts.

For the Console VI it would be a bit more difficult, as you'd need to map out what the inputs should be from the keypad, which is a bit more involved than watching for pulses on two pins. There's also a question of is there space in radio for the controller to not just be installed, but shielded so it doesn't throw a bunch of noise into the IF or other circuits. It's doable, but as Nomad mentioned it would be prohibitively expensive to pay someone to create it for you as a one off.

Finally, you could also do the DDS thing in a Console VI if you wanted to extend the frequency coverage. Might need to broadband the radio, I'm not sure how wide it is from the factory. I'm pretty sure you know the tradeoffs involved with that.

 

[Retro CB Guy]

Still would love to see some pics of your redone Console 5 though, if it's not so much trouble or time consuming TM86.

Yeah I'm game for other expansions for the Console 6 by SBE but as for broadbanding, well most Sidebander 6 mobiles and the base do well with the 99 channel readout bit which is also listed on CB Tricks. The frequency range for that is 26.7150 - 27.7050mhz.

 

[TM86]

I'll have to set aside some time to take some pics. Also some time to dig that particular radio out of it's hiding place.

 

[nomadradio]

The keyboard, PLL and channel digits of that radio are controlled by a custom chip, sometimes called an "ASIC". As in Application Specific Integrated Circuit.

It's not a programmable general-purpose gadget with clever firmware. Think of it as a circuit board full of hard-wired gate, counter, register and flip-flop devices all hard-wired for the task they perform.

If this chip fails, only a copy of the same set of guts will replace it.

Naturally, anyone with the talent and a few hundred hours to spare could simulate most of these old, so-called "custom" chips using modern flash-based microcontroller chips. Heck, I might even buy a few for that proverbial rainy day if the price were right.

73

 

[TM86]

For Retro CB Guy, the requested Console V/Arduino frankentroller pics. AKA it's ugly, but it works.

Solder connections to the back of the main board where the custom chip used to reside:


Ribbon cables labelled PLL, Display, and UP/DN:


The Arduino mega I used for the large number of IO pins, I'd do that differently now:


Channel 1:


Channel 40:


Tried to catch it between channels with the scan function on, it didn't go well:

I never did recreate the channel 9 switch function. Just too lazy to wire it in.

Now here's the sad part. The disk the Arduino sketch was saved on took a dive a few years ago. If I wanted to change anything now I'd have to start from scratch om the programming side.

 

[nomadradio]

This radio would refuse to respond to the front-panel controls. The one-chip microcontroller that runs the input keyboard and channel digit display was the chief suspect. It would power up with channel digits "00", rather than "1".

Seemed clear-cut enough. Located an organ donor and carefully removed the non-replaceable chip only to find that it wouldn't work in this radio, either.

Showed the exact same symptoms as the chip that got (carefully) removed from the radio.

Oops.

Parts you can't test become irresistible to blame for a fault you can't explain any other way. But what had to come next was to document what all 28 pins of the MM5799 micro controller were doing. Turns out to be a bug hunt. For some reason the National Semiconductor "COP" series of small processors has not been documented on line just yet. "COP" as in "Control Oriented Processor". But it turns out this family of chips was popular in some pinball machines. The pinout picture from the pinball blog web site wouldn't help much. Pins marked "coin insert" and "tilt" clearly don't apply to this radio. But those are defined inside the program. This did reveal which pin is the chip's clock input. Used to be if you couldn't explain the fault in a computer circuit board, you start by looking at the clock source for the CPU.

Oops, nothing on that pin. Trace it upstream and we come to a flat cable connection that has expired. Decided it looked just way to sketchy to repair.

It's no surprise that a new cable fixed the issue.

Should have tracked down the CPU chip's pinout and checked for a clock input before swapping the part. Aggravating part is that I probably have the original book from National Semiconductor on the COP family of controller chips. Under a half-ton of other out-of-date data books. I should probably ship them all to the Internet Archive.
But the lesson is, once again to measure once, cut twice. The SBE factory schematic shows which pins are wired to what, but offer no hint as the the intended function of that pin on this chip. Woulda got fixed faster with the chip's functional pinout on hand at the start.

Now that the channel selector works again, the problem of quirky lock/unlock issues remains. Makes me wonder how many of this model were actually produced before the company threw in the towel for good. My intutive guess is not terribly many.

73

 

[NZ8N]

I replaced the ribbon cables between the CPU control boards on my Kenwood TS440SAT, the ribbon cables were fraying every time I had to pull the CPU. I replaced the ribbons with pin headers and sockets, because the pin holes on both boards aligned perfectly. I need to dig that radio out and take pics of what I did to the CPU boards, if I ever get around to it.

 

[Retro CB Guy]

I replaced the ribbon cables between the CPU control boards on my Kenwood TS440SAT, the ribbon cables were fraying every time I had to pull the CPU. I replaced the ribbons with pin headers and sockets, because the pin holes on both boards aligned perfectly. I need to dig that radio out and take pics of what I did to the CPU boards, if I ever get around to it.

Thanks in advance !