[TenTec] Schematic for 311 Band Data Decoder? More than you ever wanted to know.

[Edward A. Feustel]

Dr. Gerald N. Johnson wrote:
> On Thu, 2009-06-18 at 14:46 -0400, Eric Rosenberg wrote:
>   
>> TT says they don't have a schematic for the 311, which apparently isn't
>> really a Band Data Decoder, but rather an inverter.
>>
>> Have any of you opened up the box and looked at it.. or reverse engineered
>> it?  I'd like to control my Herc II with something other than my Orion, but
>> am not sure how to wire it up.
>>
>> Thanks,
>>
>> Eric W3DQ
>> Washington, DC
>>     
>
> I've downloaded the 565, 566, and 420 manuals plus the data sheet for a
> UDN2982A and read the band connector data in the Tentec manuals.
>
> The outputs of the Orions is a low, one wire per band. Its open
> collector, good for a maximum of 250 milliamps which could run a small
> relay as illustrated in the manuals. E.g. its essentially a contact
> closure to ground.
>
> The input of the 420 is the same except it needs one wire raised above
> 2.4 volts to indicate the band. There 10 and 12 share a wire, 15 and 17
> share a wire and 30 and 40 share a wire. The maximum input voltage to
> the interface chip is about 20 volts. If it wasn't for the shared lines
> a couple CD4009 Hex inverter chips would do the job, with a gaggle of
> pull up resistors on their inputs (10K input to +supply and there's 13.5
> volts on the Orion band connector). The necessary sharing could come
> from a three gates in a CD4072 quad OR gate, or a half dozen diodes. Or
> those that stay one wire to one wire could be inverted with a CD4009 and
> those with two wires to one could use three gates of a CD4011 NAND gate.
> Tie the unused gate inputs to ground or supply. Adding LEDS for band
> indicators is an option.
>
> Alternative, and apparently what the 311 does is to use 11 PNP
> transistors as I described already, tying their collectors in parallel
> when the bands are shared.
>
> To run from a radio with BCD output, I'd probably use a CD4514 that
> takes in 4 wires binary and puts out 1 of 16 high. It works from 5 volt
> to 15 volt logic and supply. I know the FT-857 and 897 have that BCD
> output.
>
> The rest of the details are in the Tentec manuals.
>
> But a simple cable between an Orion and the 420 is out.
>
> 73, Jerry, K0CQ
>
>
>   
In the last year, I bought one from Ten Tec to run my 253.
I got a special cable made because the Ten Tec cable did NOT
permit the 253 to cover 30 meters. I posted the fact and the prices I paid
previously.

I can refer you to the builder if you will contact me privately.
Ed, N5EI