GTX node radio ...

Connection Points for Motorola Radios / Repeaters
K5TRY
Posts: 36
Joined: Fri Mar 09, 2012 8:25 am
Location: Springdale, AR

GTX node radio ...

Postby K5TRY » Fri Jun 28, 2013 1:42 am

HowTo - GTX - NodeRadio


GTX PP mobile wiring to v3.Board/cm108 Fob for simplex pLRI node->

---GTX Node Radio----------

2 --Tx-------- LINE OUT
3 --PTT------- 2

7,14 --jump--

14 --Ground-- 6,LINE IN/OUT(ground side)

11 --Rx-------- 8,LINE IN
15 --COS------ 7

13,16 --jump--

(S401 DIP switch pins 1,2,3,4 ON)

---usbradio.conf----------

;
; Usbradio channel driver Configuration File
;

[general]

[usb12345]
rxchannel=usb12345
;
; Parallel port V3 board - GTX
;
pp3 = ptt ; ptt, Tx
pp11 = cor ; cos, Rx
pp4=out0 ; in, cor or ctcss
pp5=out0 ; multiple pins can be set to PTT if desired
pp6=out0 ; pins 4,5,6 are AUX 1,2,3, default off
;
hdwtype=0
rxboost=0
txboost=0
rxctcssrelax=1
carrierfrom=ppinvert
ctcssfrom=no
rxdemod=dsp
txprelim=no
txlimonly=no
txtoctype=no
txmixa=voice
txmixb=no
invertptt=0
duplex=0
rxondelay=0
rxnoisefiltype=0
plfilter=yes
eeprom=0

---usbradio_tune_usb12345----------

[usb12345]
; name=usb12345
; devicenum=1
devstr=2-1
rxmixerset=285
txmixaset=420
txmixbset=500
rxvoiceadj=0.552629
rxctcssadj=0.500000
txctcssadj=200
rxsquelchadj=508

---sideNote----------

...here is updates and what i have came up with so far. I know there are multiple configurations to choose from depending on how u set your pinOuts, jumpers, and DIP switch (if the new version radio). So i will be exploring, teSting, and searching ways to interface GTX radio...
Last edited by K5TRY on Sun Jul 14, 2013 11:42 pm, edited 3 times in total.
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K5TRY
Posts: 36
Joined: Fri Mar 09, 2012 8:25 am
Location: Springdale, AR

Re: GTX node radio ...

Postby K5TRY » Wed Jul 10, 2013 2:10 am

---!NOTES!----------

The reconfigured pin functions of accessories connector J400 are as follows:

J400-12
-- is an input to the radio which allows the data modem to mute the radio’s speaker audio while data bursts are being received. The modem pulls J400-12 low, which is routed through switch U402 from pin 14 to 1, and turns on Q415 and, therefore, Q401. This pulls U401-8 low, muting the audio power amplifier.

J400-4
-- is an output from the radio which tells the modem that the radio is transmitting by pulling J400-4 low. Two non-simultaneous conditions are summed to recognize transmit mode under all timing conditions. If PTT is low, Q410 is off and a high is provided via R440, D403, U402 pins 12-13, and R411, to turn on Q411 and pull J400-4 low. If the transmit-enable voltage K9V1_ENABLE is high, a high is provided via D403, U402 pins 12-13, and R411, to turn on Q411 and pull J0400-4 low.

J400-15
-- provides system busy indication by observing the status of the AUDIO_PA_ENABLE line, which is low during active receive conditions. This low is provided to J400-15 via D402, indicating a signal is being received.

J400-3
-- is DATA_PTT input to the radio, routed via switch U402 pins 4 to 3, to U101-8. The ASFIC (U201) is configured for FLAT_TX_AUDIO when DATA_PTT is asserted at U101--8.

J400-5
-- provides a FLAT_TX_AUDIO input to the radio, via C418 and gain-reduction buffer U202 (pins 1, 2, 3), to U201-D7. This connection is always provided and is not reconfigured by the setting of switch S401 (1-3).

J400-11

-- provides a Flat/Unmuted RX Audio Output from the radio. This audio is obtained directly from detector U5201-28 via C230 and R236, is routed from U402 pin 10 to pin 5, amplified by U403 and applied to J400-11 via R419 and C419.

---RSSI_BUF----------

... For special applications, a DC voltage proportional to received signal strength can be provided to J400-15. This requires removal of resistor R430 and diode D402, and insertion of resistor R215. The DC signal-strength voltage is provided by detector U5201-11, buffered by U202 (pins 12, 13, 14), and routed via R215 to J400-15...
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K5TRY
Posts: 36
Joined: Fri Mar 09, 2012 8:25 am
Location: Springdale, AR

Re: GTX node radio ...

Postby K5TRY » Sun Jul 28, 2013 9:41 pm

HowTo - OLDER MODEL GTX - Node Radio


GTX PP mobile (without DIP SWITCH) wiring to v3.Board/cm108 Fob for simplex pLRI node->

---GTX Radio Without DIP Switch----------

2 --Tx-------- LINE OUT
3 --PTT------- 2

4,10 --jump--

7,14 --jump--

14 --Ground-- 6,LINE IN/OUT(ground side)

11 --Rx-------- 8,LINE IN
15 --COS------ 7

13,16 --jump--

---usbradio.conf----------

;
; Usbradio channel driver Configuration File
;

[general]

[usb12345]
rxchannel=usb12345
;
; Parallel port V3 board - GTX
;
pp3 = ptt ; ptt, Tx
pp11 = cor ; cos, Rx
pp4=out0 ; in, cor or ctcss
pp5=out0 ; multiple pins can be set to PTT if desired
pp6=out0 ; pins 4,5,6 are AUX 1,2,3, default off
;
hdwtype=0
rxboost=0
txboost=0
rxctcssrelax=1
carrierfrom=ppinvert
ctcssfrom=no
rxdemod=flat
txprelim=no
txlimonly=no
txtoctype=no
txmixa=voice
txmixb=no
invertptt=0
duplex=0
rxondelay=0
rxnoisefiltype=0
plfilter=yes
eeprom=0

---usbradio_tune_usb12345----------

[usb12345]
; name=usb123451
; devicenum=1
devstr=2-1
rxmixerset=125
txmixaset=420
txmixbset=500
rxvoiceadj=0.625000
rxctcssadj=0.500000
txctcssadj=200
rxsquelchadj=508

---sideNote----------

...Here is how to mod an older style GTX mobile w/o the DIP SWITCH to tap and feed the COR for COS. Ive included 2 pix showing where and what and another showing after the tap and feeding to pin 15. I am now satisfying Asterisk with 4.21v COR and using rxdemod=flat in usbradio.conf... ENJOY!

Image

k5TRY
Attachments
tryGTXcos.jpg
tryGTXcos.jpg (862.49 KiB) Viewed 9055 times
gtx900a-COR.jpg
gtx900a-COR.jpg (192.92 KiB) Viewed 9055 times
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KJ6KO
Posts: 2
Joined: Tue Jun 25, 2013 10:56 am

Re: GTX node radio ...

Postby KJ6KO » Sat Aug 03, 2013 11:27 am

Just an FYI, Pin 5 "Flat Tx Audio Input" does NOT work on a GTX. If you have one that does, tell me how you made it work! Tried it every which way I could with several radios, NO output audio. Was forced to use MIC audio in and change system audio to "spkr" (de-emphasized) audio.

K5TRY
Posts: 36
Joined: Fri Mar 09, 2012 8:25 am
Location: Springdale, AR

Re: GTX node radio ...

Postby K5TRY » Sun Aug 04, 2013 7:47 pm

KJ6KO wrote:Just an FYI, Pin 5 "Flat Tx Audio Input" does NOT work on a GTX. If you have one that does, tell me how you made it work! Tried it every which way I could with several radios, NO output audio. Was forced to use MIC audio in and change system audio to "spkr" (de-emphasized) audio.



Pin 5? "I dont use no stinkin pin 5!" lol ...

Here is a helpful tip / clue about pin 5 from the service manual... Let m know if u need anything :)

Transmit Audio Circuits

Mic Input Path
The radio provides two microphone inputs, one on the
control head (internal mic audio) routed through J101-
16), and one on the accessory connector J400-2 (external
mic audio). The two inputs are connected in parallel.
The dc bias required by the microphone is provided
by resistor R205, derived from the 9V3 source and filtered
by R204 and C209. The microphone audio signal
is applied via R206 and C211, to the ASFIC at U201-B8.
Filter capacitor C210 provides low-pass filtering to
eliminate frequency components above 3 kHz, and
C211 serves as a DC blocking capacitor. The audio signal
at U201-B8 should be approximately 80mV for 60%
of full system deviation.

Flat Tx Audio Input Path

The FLAT_TX_AUDIO signal from accessory connector
J400-5 is buffered by op-amp U202-(1-3) and fed via
C205 to the ASFIC U201-D7.

PTT Sensing and TX Audio Processing


MIC PTT is sensed by the mP. PTT can also be generated
by grounding pin 3 on the radio accessory connector,
J400. When microphone PTT is sensed, the mP will
always configure the ASFIC to enable the mic audio
path. PTT can be configured to enable the EXT_MIC
audio path when J400-2 is connected with an external
mic audio input. Data PTT is configured to enable the
flat transmit audio path (when J400-5 is configured for
FLAT_TX_AUDIO)!!!!!!


Inside the ASFIC, the mic audio is filtered to eliminate
components outside the 300-3000Hz voice band and
pre-emphasize. The capacitor, C231, between ASFIC
pre-emphasis out U201-C8 and ASFIC limiter in U201-
E8 AC couples the signal between ASFIC blocks and
prevents the DC bias at the ASFIC output U0201-H8
from shifting when the ASFIC transmit circuits are
enabled. The signal is then limited to prevent the transmitter
from over deviating. The limited mic audio is
then routed through a summer which is used to add in
signalling data, and then to a splatter filter to eliminate
high frequency spectral components that could be generated
by the limiter. The audio is then routed to the
VCO attenuator, which is tuned in the factory or the
field to set the proper amount of FM deviation. The TX
audio emerges from the ASFIC at U201-H8 MOD IN,
and is routed to the RF section as MOD IN.

73

k5TRY
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