Realistic Pro-2006   Unit: B “Bravo”. (Experimental).

One of the golden greats of 1990s scanner radios the Realistic Pro-2006 (also known as the Comtel 205 in European markets) was made for Radio Shack/Tandy by General Research Electronics Inc (GRE) Japan and designed and assembled in their factory in Chiba Prefecture.
To quote radio reference.com
“The Pro-2006 is considered by many to be the best scanner ever produced in terms of sensitivity and selectivity.”
This model has great design and is much loved by airband fans due to its brilliant AM performance , no gaps coverage of both Civil and Military airband and beyond from 25mhz up to 1.3ghz . It has top quality components which very interestingly are a mix of traditional/older THT (Through Hole Technology) mounted components and SMD (Surface Mount Devices) like the ones found in iphones and the like today.

History

In the early days of Surface Mount Device production and implementation, Japan was the centre of the industry.
Nobody, but Nobody even came close.
What are SMDs ?

Quick photo from todays work bench in an attempt to show Surface Mount Devices (SMDs) and how much they changed electronics in terms of physical size.

This stuff was lying in the spares box and the bits shown here are about 5 years old or so.
Here we see some regular Trough Hole Technology 1k resistors and some SMD 4 x 22 ohm resistor packs.
You can see the 8 little tracks leading in and out of each SMD, one in and one out of each of the individual 22 ohm resistors.
There is a tantalum capacitor SMD to the lower right shoved in between 2 resistor packs..
Also at the left in there is the point of my regular disposable paper mate ball point pen.

As said these are are a few years old, there is a smaller resistor pack package now reduced by around 40%. Same power rating..crazy stuff !

Unlike today, SMDs were very very expensive. They offered manufacturers the advantage of making their final products much smaller . For example , A capacitor or resistor could be made 1/20th of the size of a regular (THT) one. The SMDs could be glue mounted on to pcb boards by machines or robots then the board pcb run through yet another machine and bath soldered…ground breaking. Even today the process of “pick and place” is a commonplace in the electronics manufacturing industry but non the less it is an amazing process to watch.
It was Japanese companies that reduced manufacturing costs and SMD devices started to appear in their fine consumer electronics. This was a major change as such technology was previously reserved for Aviation and Defence products manufacturers who had Govermnent backed unlimited budgets.
At the start,35mm Cameras made by Nikon and Canon were in a surface mount device stratosphere right up there all on their own. Built in motordrives, super relaible autofocus and smaller,longer lasting batteries became reality.The Surface Mount Device was here to stay and there was no turning back.
Perhaps the most iconic “ordinary” low cost devices created by smd technology was the Sony Walkman family of personal cassette and radio cassette players of the 1980s. They were compact, portable and sounded great. Surface mount chip devices were used in these, sometimes bonded on to the ribbon cables and becoming part of the cable harness itself and sometimes SMD components were used in pcb sub boards around the unit. Some walkman models had fancy light touch then called “fuzzy logic” controls the experimental forerunner of Jog/Shuttle controls seen later on Sony VCRs/Hi-Fi and Camcorders with tiny but utterly relaible digital servo motors.


The cassette player shrunk significantly,seemingly overnight without anyone really noticing. The batteries were smaller and they lasted longer. Meanwhile the mains powered cassette radio was dead or as good as…Older mains cord fed/battery radios of the 1960s and 70s seemed like Dinosaur relics of a distant age all within 12-18 months of the first Sony Walkman device emerging. Other manufacturers copied Sonys lead . Sales were huge. Surface Mount Device was here to stay and there was no turning back.
Later on in History
Sony brought SMD to the Philips Compact Disk/”digital audio party”, Two truly great companies in perfect partnership. The playstation came along using philips’ compact disk as a media to store the games and the rest is history, this team of 2 consumer electronics giants were an unstoppable force in digital entertainment, and they continue to be at the very top of their “game” to this day. 

The Walkman changed the way people listened to music and with the radio option,sports and current affairs. You could listen on the bus, train or walking ,An early form of podcast device if you like.. the forerunner of the ipod & mp3 player.
Tooling for SMD wasnt cheap so only the “big boys” could afford the many millions of Yens & Dollars it costs but somehow GRE Inc were in there very early as well so I can only assume that this was a huge investment for GRE no doubt backed by US money from Radio Shack Inc.
In terms of market, the USA and Canada had and still have a huge customer base for scanners.
European sales were/are very small in comparison.

GRE really were using cutting edge technology as very few hobby type devices used SMD due to the high cost. Looking back , it seemed that GRE wanted to incorporate new technology straight off. The GRE hand held units had a good reputation using very early SMDs . With the pro-2006 it wasnt as if they were short of space to mount the components as the casing has plenty of room unlike a hand held scanner.
GRE Japan finally sold out their scanner side of the business to Whistler Group of the USA not too long ago back in 2014 but the GRE “DNA” is still evident in todays Whistler scanner models.

Back to the radio

Anyway enough of devices and history,now more about this particular Pro-2006.

I spotted this unit for sale on Gumtree in the South of England, it was quite cheap for a 2006 but advertised as working okay.
I already have one of these fine machines featured in a earlier post but there are a series of modifications I wanted to try so this cheap unit seemed destined to become “radiostationx’s Pro-2006 unit number 2 experimental” testbed.
I asked fellow telescope spotting friend Paul who lived not too far away if he pick it up for me, Paul managed to negotiate £5 off the asking price..Well done Paul !
He picked up the radio and dispatched it to me via courier and I eagerly waited for the parcel to arrive.
He mentioned that the owner hadnt used it for some time but he said it worked fine & he liked listening to emergency services on his Pro-2006 some years ago.
On arrival I unboxed it and quickly tried it , dead or as good as..a very distant hiss from the speaker , no display no buttons working…oh dear.
Power off and have a look inside.
The unit was in a very sorry state, but the smell was truly awful..I was told by my better half to “get that thing out of here” ! It was a very bad , damp musty smell. Horrible.

I think the previous owner may have had a cat. Enough said.
I retreated to the garden and removed the covers,
Here are some photos of the unit.

Dirty Front Panel

Dirt and grime on the control knobs.

even though I was outdoors the smell was worse when the casing was off..

Hair, dust and the awful smell !

I have never seen one as bad as this, such a lovely radio in its day, now full of grime and very unloved. The muck that came out of it was unreal !

Baby wipes to clean up the horrible mess.

The speaker dust cover

I looked at the mains input cabling and transformer all was well on this one thankfully unlike my previous Pro-2005 model (Essentially the same as a Pro-2006 with some very minor differences) which was waiting send someone to the hospital or undertaker !
The 9v duracell battery was vintage March 2001 on the sell by date and had burst its casing inside the scanner some years ago by the looks of it.

The top end of the battery was leaking also.

I cleaned the main (linear) PCB board of loose hair/dirt and grime with a brush first then the boards were cleaned with isopropanol on Q tips to get a better look inside and gave the outside casing and buttons yet another clean with another load of baby wipes. I used a whole pack in the cleanup.
The smell has gone. I think I can safely take it inside without fear of being shouted at now !
Its starting to look a bit better.

I powered up again and looked around the main linear board for faults with some test gear and a wooden kebab skewer as a make shift non conductive probe aka “dibbler”.
I soon found an issue . The 5 volt regulator IC8 . The screw securing the regulator heatsink to the chassis of the radio was loose. One of the leg solder joints onto the pcb was in very bad shape indeed and the leg wasnt touching the contact pad on the board. The regulator is shown here by he arrow.

Note the much improved PCB condition following the clean up with isopropanol.

That hard to spot bad joint lives under that little bunch of cables to right of the MC7805C 5 volt regulator (IC8).
Re-soldering the leg on to the pads on the linear PCB and tightening the chassis heatsink screw I switched on to try things out and the 5 volt rail came back up and as if by magic ..the radio sprung into life .

There is a deafening crackle at switch on due to dirty wipers in the on-off-vol control pot, the backlight is very dim, I noticed a small crack in the top edge of the front panel.. but the radio is working so thats the progress report so far.
I will have to get the front panel off to make repairs to the hairline crack and to clean out that dirty potentiometer properly and make some enhancement modifications.
A selection of components are on order for the mods .
Watch this space for updates.

Edit : As if by fate, I noticed that featured in the last photo above is my trusty Fluke multimeter, Who makes those ?  Our friends from that fine company from the Netherlands, Philips of course !