What Was The Pearce Simpson Simba SSB/2?

[Orbieswar]

I like where you are going !..

Orbieswar

If you want, you are welcome to the mod I am going to do to the Simba. I already tested the dual color LED idea last night. I use a Red/Green LED to produce yellow and green. When it is yellow, the channel indicated looks like the stock amber color, and when it is green, the channel indicated is green. My plan is to drive the LED and the 858 with a 28 pin PIC microcontroller like in the video. I will intercept the 10 wires coming from the channel selector and have 10 replacement lines coming from the PIC going to the 858. If you pay for the parts (about 5 bucks) and the shipping, I'll program the part for you. This assumes I get the Simba working, since the ebay ad says it is not.

tink

The chan selector uses a white lamp however it passes threw 2 filters.
From memory the first filter is amber the second filter with the numbers is orange, or is it the other way around ? hmmm
So I don't think the green will pass threw very well and the red may wash out...
However The signal meter ( on the cheetah ) uses a lamp with a yellow filter for RX and switches to another lamp with a red filter for TX. If the meter were to change to green for the second bank I think that would look awesome...Even better on the samba !!
I recently replaced the chan selector in my D858 Madison. This got me thinking .... All D858 SSB radios have the same code. I thought what if I acquired another switch with LED readout and mounted it externally of the radio in its own box.( like the Digiscan ) This would leave the cosmetics untouched and add a modern touch with full 40 channels no gaps ( except the Alpha gaps ) As I am only using this radio as a home unit the remote/satellite chan selector is not an issue...
But yes I do like your idea and am interested !!

 

[tinkyr]

Simba Mod

Orbieswar

I have already put in the dual color LED. If I make it yellow, then the channel has a stock looking amber color. If I make it green, I can see Green, but the shade might be a little close to the amber for most people to notice. When I put the red color in, it does come through, but a bit attenuated. I ordered some "ultrabright" LEDs last night and I will see how that works. I'll post some results here and hopefully a video when I have some results. Thanks for your interest.

tink

 

[Orbieswar]

That's great. news..I did not realize you had the radio already....Are you able to put up some internal pics of the radio ? And is she still going ? I hope so

Orbie

 

[tinkyr]

OK.. this is officially the answer to the original question in this thread

Here is a picture of the SSB/2 and the guts under the hood. I also showed the original chassis without the PLL module and the crystals on the left. I will post some pics and a link to a video when I am done with my subtle mod to make it 40 channels

 

[Dawn]

Just a preliminary look at the Courier Cenurion PLL-40 in the SAMS 290 photos, this looks precisely the same physical layout right down to the holes in the chassis with grommets, power supply board, transformer numbers, and the heatsinking/brackets. Only exception is the front panel switching which was unique to the brands. So it appears it's not only the board, but the entire physical chassis layout.

When I get feeling a bit better, I'm pulling the Centurion junker that I have and will take some pics for a chassis to chassis comparison. I mentioned to Orbie about finding a junker mobile Gladiator and substituting the switch. Does this switch maybe have a stop in it and it's capable natively? The Centurion 40D had a digital display added, but they essentially just added another ganged BCD switch that was sequential rather then programmed with the us bandplan gaps to sequence the digital display from 1-40. Easy and simple in theory, but finding a raw switch won't be easy short of cannibalizing nowadays for the straight binary version for the display or do this with a PIC and rotary optocoupler/sequencer.

I don't know about the 40D, but the RS TRS 457/8 are a slightly different board even though the topology is much the same, just rearranged a bit and some different semis in the audio output and modulator stages and less tuned stages. The early Palomar 500 was supposed to be the same as the TRC-456. The chassis layout looks nothing of the sort as the above which are literally kissing cousins.

Many of these early PLL 23 channel radios were designed with future expansion in mind and sold under unusual circumstances as people were witholding purchases until the expanded band plan issue was settled. These newer, 23 channel pll based radios were tacity being sold that future upgrades would be likely possible by the distributors. I was still working in RS when the TRC-57 came out that looked like the 40 channel trc-457/8 that came out later with an analog dial. Totally different beast inside then the '858 chassis, but the district manager pushed the idea to increase sales by suggesting that these PLL radios would be possibly upgradable although nothing was put in writing. It wouldn't make sense that Uniden made this first gen board that was identical in several 23 and 40 channel chassis and have two separate switches for the analog dial versions. Not how scale of economics works, nor does the reapplication of type acceptance. Only wild card at the time was how many channels were to come at design time. To my knowldege, at least one company did make the claim their radios were expansion channel ready by sending it back to the distributor and that was Sharp. They did make good on the promise, but didn't upgrade the unit, but sent another that looked just like it in it's place. This may have something to do with the EIA pushing for the FCC to immediately ban the resale of used 23 channel or channelized sets or NOS 23 channel inventory that accumulated while the public waited with the intention of setting off a new wave of consumer spending on new sets. Hence the possible refusal of dual type acceptance.

There was also a design dicotomy that was going on. Estimates on how large the new channel pool would be also would have determined design considerations as if the larger, anticipated pool would have required a more broadband design rather then keeping the tighter specs similar to 23 channel chassis.

I can't confirm this, but the Courier 40 channel units would not do the 200+ channels that the RS/Palomar units could. Hitachi for example waited it out with no 23 pll chassis and essentially designed their 40 channel OEM sets based on the limited channel pool and tigher specs of the older crystal hetrodyne topologies of their older units once they knew for sure. That may have been too late for RS to place orders and the reason they switched to Uniden, but mass retailers like JCPenny and Sears could afford the wait due not being dependent on CB sales for survival in a recessional economy of the time.

Uniden may have had two designs, one tight and one wide just in case to take orders and get to the market faster while still producing 23 channel sets.
I imagine this same bit played out with other distributors like Cobra/Dynascan and Midland among others that used variants of these boards. Both boards appear to be concurrent during the 40 channel days.

Can anyone confirm this? Was there a wide and a narrow version? No question that Uniden was making both at the same time or using up their 23 channel version stock while pursuing new type acceptance in new models.

Possible hypothesis on the subject.

 

[tinkyr]

Simba Siblings

Hi Dawn

I used to be really interested in these radios 30 years ago, but never thought I would be again. This all started out of a nostalgic desire to have a "Big Radio" that had the rugged '70s look. The Simba was my answer. As luck would have it, I have a Sams 290 from my old days of working on radios, and you are correct, it is identical. I took the cover off the PLL module and it is also identical. I compared it to Orbieswar's pictures of the Cheetah SSB/2 and it appears to be the same radio.

Orbieswar had speculated that the board was the same as the Midland 79-893 (Sams 211) but it seems to be different. There is an excellent schematic on CB Tricks for the Midland, and the board is very similar, but there are differences. The most obvious differences are that the Midland has a single IF of 7.8 MHz, where the Simba/Cheetah/Courier remix the AM receive path down to 455 KHz like the Cobra 148 does. Another difference is that the Midland has three crystals around 11.2 MHz like the 858 board in the TRC-457/8, whereas the Simba uses two. It does look like the PLL module is the same in both units, there is just some unpopulated thru holes on the Simba PCB.

I want to make some comparisons of the Simba/Cheetah/Courier design to two other designs, that being the 858 board in the TRC-449/457/458 and the Cobra 148. I will refer to them as the "148" and the "449". The Simba seems to be a hybrid of the two, but mostly resembling the 449 (Sams 200). In fact, the 27 MHz XMIT on the Sams for both models after the mixer (34 & 7.8 MHz) look identical and are even drawn on the same part of the 4 page fold out. The entire RX front RF Amp, Mixer, IF Amp, Crystal Filter and detector stages look 95% the same. The noise blanker circuitry with the UPC577 looks the same too. The Audio output/modulator stage is very similar, except the Simba uses a UPC1020 and the 449 uses a UPC1156. I checked and the two devices do not have the same pin-out.

The main difference between the Simba and 449 is the Input audio stage is all discrete transistors vs the UPC592 mic amp in the 449, as well as the 455 KHz AM IF. The 455 KHz circuitry is not that similar to the 148 though. The 148 basically uses one serial IF string with 455 KHz in parallel with 7.8 Mhz. The filters are in parallel, and the IF cans in the IF amp are literally in parallel. In the Simba, there is a Mix of the 7.8 IF with 7.34355 MHz to produce 455 KHz and then the 455 KHz IF is a complete separate string.
The PLL section of the Simba and the 449 is very similar, with the obvious exceptions of the module and the 2 vs 3 crystals.

Before I leave the radio comparisons, I have included a side by side comparison of the Simba board I have and the drawing for the Midland. Even though they are similar, my picture shows the differences in 455 KHz section and crystals in the PLL module. If you look at the Module in the Simba, you can see the area with no parts to the right of the two crystals where the third one would go.

To answer your questions Dawn, the channel selector has 24 positions and there is no stop. When it is on the position between 22 and 23, it appears that the lock detector is disabled and there is no transmit or receive. Curiously, the switch on that position puts out the BCD code for 27.135 instead of 27.235. They obviously did not bring out the +10 signal on this position, so even if you disable the out of lock detector, you won't get 22A (24).

I would encourage you guys to wait for the results on my channel mod to see how it works out. I should have all the parts in a couple weeks, and I will post some pics here and maybe a youtube video. I think keeping the stock channel selector look is worth it

tink

 

[Orbieswar]

Family Gentetics

Thanks Tinkr for the clarification on the differences...
I noticed there were some minor differences in the PLL area, but thought nothing more of it at the time. I bought the Midland manual as it showed me the PCB layout for the Channel selector which I needed at the time. (Now I need another !)

And thankyou for posting the pics.. As suspected it is the same as the Cheetah/2.. I have never seen the R/S models as reported.. I thought they used the same chassis as the 139xlr/Grant D858 ??

I wonder what Uniden were up to with these chassis ?? As Dawn posted was it because they did not know how broad the allocation would be ? Were they playing with specifications and tolerances ? testing the waters as it were ?

I Would have thought though with the pending expansion and unknown width, that these early designs may have been more broad banded than the later more common production chassis and not less as Dawn has suggested ?

Dawn.. Does the Courier brand have the old school type channel switch as the Simba/Cheetah ? or is it the same as the Midland which uses the more common green switch and PCB ..Was there a difference in the selector design between the 23 & 40 with a PLL ?
The Cheetah/Simba to me does not look as if it was ever thought of to have had 40 channel switch retro fitted., simply based on it selector design. ( or was it ?) Where as the later models eg Midland with its conventional selector ( as we know it) may have been. atleast they would have been much more easier to replace.

a very interesting topic gentlemen very interesting !

 

[tinkyr]

858 Genealogy

Hey Orbie

If you want to know what the channel selector is like, check out this drawing for the 23 channel Gladiator. Between that and Sams 290 I think you have all the documentation for the radio.

http://www.vkham.com/Info/manuals/d858/Gladiator PLL Schematic.jpg

tink

 

[Dawn]

Here's two interior photos of the Centurion PLL40 for comparison.

 

[Dawn]

To Tinkyr's question about the switch, it's an enclosed, green rotary BCD and not the open frame phenolic like the Simba above. It's mounted on a sub PC board and direct wired.

Even though I haven't been inside a 40D, the digital display version only differs by adding a two digit display that's driven directly by a 2nd ganged switch based on the SAMS litterature.

 

[Orbieswar]

Uniden Family History

Dawn great pictures... Makes sense that the 40D would use the conventional green switch...
Tinkyr Thankyou for the link.. I went looking and found some more info... But no schematic for a Gladiator 40PLL !! they all deal with the 23 open switch. Was it the old open type or green ?? Never mind I sorted mine out with the Midland book. But still interesting I think..

Now where can I find a CB290 manual ?

I might get flamed for this But Dawn you will enjoy this... I found on another forum some info on early Uniden history and the possible reason why Uniden changed chassis designs..... Also the author mentions that Uniden were the new kids on the block..

I find this puzzling as Uniden were making chassis well before the PLL or the other brands he mentions, Or so it seemed here in Australia.

Bit of a read but I think its good... end the last author is the cream in the pie !

858 PLL Mods and stuff | WorldwideDX Radio Forum

 

[Dawn]

Thanks for posting the link Orbie.

I just read through the 2 pages. I have to question the "2nd generation" board as both were concurrently made. Perhaps it's true and Uniden stockpiled first gen boards that were already contracted for and proceded to manufacture 2nd gen boards that were used to fill later orders. If anything, 2nd gen boards are cheaper made and I would think the selectivity is much better on the first due to the dual conversion unless the later board had a really good xtal filter. That cost difference would vastly offset the savings of dual conversion and second ceramic filter. My understanding was that the TRC-459 is a further cheapened version of the 457/458 boards. I need to sit down with the docs and confirm this. I think I have a .pdf of the 459 on a cd somewhere.

IIRC, the 23 channel Simba used the parallel IF's as well with 455 being am and the higher one SSB. That was a major gripe a lot of owners had that the radio was very susceptible to bleed over on AM but good on SSB. There were mods chaining several ceramics with an extra stage of gain on a wire in board for radios that had this arrangement or single conversion AM sets with a cheap ceramic. I think that Lou Franklin still sells a version of these.

Why would I flame? Very interesting reading and very engaging thread. Really appreciate the link.

Wish it was always like this here.

 

[Orbieswar]

Tnkyr How is tricking the selector going ?

 

[tinkyr]

tricking the Simba

Hi Orbie

I had a slight setback. I ordered a processor that is 3.3V instead of 5V. I use the 3.3V at work a lot and kinds overlooked that. I am going to go forward and get a pin compatible later. I thought you would like to see the LED part that I just finished. I am using a *super bright* RGB LED in the picture below. On the left is the original lighting with the grain of wheat bulb. You can see the amber color, and how it kinda bleeds over into the adjacent channels on the knob. On the next picture, you can see my amber color synthesized from red and green. I varied the current on the red until the result was about the same as the original. I have put a heat shrink tubing shroud over the LED to kind of focus the light so you can see it does not bleed over into the adjacent channels. I think it looks better. The amber color will be used in the "Stock" mode, and the red for below ch1 and the green for above ch 23. The red is actually redder than the pink look in this picture.

I am going to start on the board today. I will take some before and after pics.

tink

 

[Orbieswar]

Are Cats Colour Blind ?

WOW That's awesome !! I am really surprised at how well the green punches through.
Considering there is atleast 2 ( amber/orange ) filters infront of it.

The amber is brilliant, Even the red looks great.

Excellent work Tinkyr !!

 

[tinkyr]

more news on the SSB/2

I removed the PLL module tonite to do my mods on it. I did not have to do much. This module is slightly different than the 40 channel modules. In the later 40 channel modules, pin 19 (the divide by 40 pin in BCD) is directly connected to ground thru a direct trace. This can be seen in the picture below from a 40 channel Midland using this module. In this Simba module, the PCB was designed to bring the pin out of the module and it has PCB accommodations for the 4.7K pulldown resistor and the .01uF cap to ground that all the other BCD pins have. This module was designed to allow up to 199 channels. They instead used the wire that would have been the divide by 40 lead and used it to detect the position between channel 22 and 23 and then OR it with the out of lock detector on the 858 to disable transmit in that position. They used the 4 PCB holes that would have had the cap/resistor to ground to ground pin 19 and allow a resistor under the board to be installed as part of the OR circuit

 

[Dawn]

Thanks for the circuit analysis in this unit. This seems to support my contention that they started in early on the proto-expansion effort before the FCC finalized the current bandplan with an early and later board design. This board then would appear to have been designed with the maximum possible expansion and the later board was honed to the 40 channels and possibly developed to come in at a lower price point due to market competition dropping prices for volume over margin.

The prevailing rumor bandied about the time was that this was going to be around 100 channels. Internal squabbles with IRAC/then Federal frequency management refusing to cede spectrum curtailed the expansion to just 17 more.

If one thinks about it, the Feds really screwed over the industry several times that must have cost millions and led to the destruction of many companies.


While this debacle/waiting game was going on, there was a concurrent R&D effort underway to produce the proposed Class E CB FM radios using some of the 220 spectrum from the amateur band. To my knowledge, Midland and Cobra had orders in for pre-production units that were in final phase of development when the FCC called the effort off. Both were rebadged as amateur 220 products with the rest being sold by Clegg under their name in the states to dispose existing inventory waiting for final approval.

 

[tinkyr]

Simba PLL Module

Dawn

I would say the objective evidence supports your contention all the way. I have taken a picture of the bottom side of the module to compare with the later version. This is with the out of lock resistor removed. You can see that Pin 19 was treated identically to the rest of the BCD pins in this version of the PCB.

Speaking of he FCC and 200 debacles, I was on 220 in Los Angeles back when they took part of that spectrum. I was on a simplex group and when the bottom part of the spectrum was lost, those people went somewhere else, and it was not to existing repeater pairs.

tink

 

[Orbieswar]

This is very informative.... Excellent work Tinkyr...

Dawn are you able to confirm the PCB layout of the Centurion PLL ? The schematic shows pin 19 tied to ground as it should.. However there is no underside pictures in the manual showing the PLL tracks. Is it the same as the Simba for pin 19 ??

Dawn also if as you say that the Simba 2 may have been designed with maximum channel expansion in mind.. Is it possible then that the Simba would expand easier with less modification to its existing circuitry ? ( broad banding )

I still find it hard to believe that this radio never had any more than just 23 on the dial... Why it was never continued on into the 40 chan format.

Could this have been around the time Pearce Simpson turned to Cybernet ?
Was is the cost of Uniden chassis ?

The Super Bengal was a great radio and can certainly hold its own .. But its a far cry from the looks and personality of the last Simba

 

[tinkyr]

23 channels

Hi Orbie

Nobody is saying it ever had more than 23 channels. I am just saying that clearly the bottom of the PCB supported more and the engineers had that it in mind to have more (up to 199). It was never used, but it looks like they were ready to pull the trigger if it was approved by the feds. Dawn is saying this with even more background to back it up. After it was clear that the amount was going to be 40 channels, it appears some of these modules had the artwork changed and pin 19 was physically grounded

The later Uniden 858 design without the module, like the TRC 449/457/458 had that pin grounded right out of the chute.

tink