Paul Metzger wrote:
>It is a T800 Series 1 Slimline which requires the PROMs to be
>programmed. I need documentation, software, and to find out what
>hardware (exact models) I will need to acquire in order to program
>the proms, including cables.
>
>All it has is a single rack panel with a T855-20 Receiver, T856-20
>Exciter/Amplifier and a terminal strip attached. It has a date on it
>of October 1996.
>I need documentation in order to find out how to interface it to a
>homebrew controller, which will then tie into an AOR Digital Voice
>modem.
>
>I hope to make it into a repeater for the Digital Voice Amateur Radio
>Association.
>
>Any help will be much appreciated !
>
>Thanks !
>
>Paul Metzger
>KQ6EH
>
>
Paul,
Unless the frequency you are planning to use is a multiple of 100KHz,
the Tait Software wont work in southern California (SCRRBA area) as it
cannot generate anything except 12.5 or 25 KHz channels and we use 20KHz
channels. You will need to find an EPROM eraser and programmer that can
program the EPROMS within your units.
The formulas for generating the hex values required are (hopefully this
will be readable once posted):
WORD 1 2 3 4 5 6 7 8
REG M M M A A R R R
BIT L 0 2 6 0 4 0 4 8
BIT M 1 5 9 3 6 3 7 10
| | | | | | | | M A
CH # | | | | | | | | TX FREF=200KHz
0 08 0E 0A 0E 00 0A 00 00 698 14 446.860 TX USING 10 KHZ STEPS
1 08 0E 0A 00 01 0A 00 00 698 16 446.880 TX USING 10 KHZ STEPS
RX FREF=6.4MHz
0 00 0B 09 06 00 00 04 01 620 06 441.860 RX USING 10 KHZ STEPS
1 0C 0A 09 08 00 00 04 01 620 08 441.880 RX USING 10 KHZ STEPS
TX FREQ(MHz) = M * 0.64 + A * 0.01
RX FREQ(MHz) = M * 0.64 + A * 0.01 + 45
Here is the pinout for a stock 855rx and 856tx:
pin 855 856
1 line out 1 line in 1
2 line out 2 line in 2
3 line out 3 line in 3
4 line out 4 line in 4
5 RSSI TX Enable
6 Audio 1 Audio 2
7 Audio 2 Audio 1
8 Speaker CTCSS
9 +13V +13V
10 +13V +13V
11 Gate/COS out Opto-key +
12 COR 1 Opto-key -
13 COR 2 TX key / PTT
14 Ground Ground
15 Ground Ground
You will need to locate a manual for the T855 & T856 as there are many
possible internal configurations possible due to multiple internal
jumpers. If anyone has the manuals in PDF form, I do not know of them.
Ed Yoho
WA6RQD
