DISPLAY UNIT

1. CONTROL of the display unit.

To easy installation remove the unit from the PA: Unscrew the bottom and the top cover at the first. Remove the grid plate from the right top side of the amplifier. Unscrew the 4 screws from the frontpage. Unscrew the 3 screws from the display panel and remove the unit.

Connect +5V to pin 8 of JP2 and +12V to pin 7 of JP2 connector from an external power supply.
For easy check we need a small external supply: connect 4k7 linear potm. to pins of 9V battery. We will have a cheap and easy PS to check the functions of the LED bargraphs. (If you have another DC PS you can use it for the tests)
Connect a jumper to RESET coonector pins and  put please 2k2 resistor to the pin 11 of the JP1 connector and to the ground.
(FWD input)

a./ RF out bargraph
Set our small external PS to +1.5V out and connect  the middle pin of the poti  to pin 11 of the JP1. If the FWD RF out meter works properly the first or second yellow LED  will lit on RF out bargraph. We can set the RF meter sensitivity with P1 (5K) poti on the panel.
If everything is OK, we will calibrate the RF meter later with help an external power meter.

b./ RFL pwr bargraph
Connect our small PS to pin 4 of JP2 connector. Set +0.8V with poti before. Few green LEDs will lit now on RFL bargraph. Set now
the input voltage till the first red LED will lit on the bargraph. We will calibrate now the fault level of the RFL bargraph with the P2 poti.
Set the P2 poti until the RFL fault LED will blink. We will see on the indicator led D68 when the RFL protection will active.
Please reduce the input voltage with the PS poti and try set up again to check the correct level of the led bargrap and the protection level. (We can reset the RFL leds if we removing the jumper from the reset connector for short time..)

c./ Ua (HV) meter bargraph
Set please our external small PS to +2.5V output. Set please the P4 poti full right clockwise position on the display unit.
Connect the small PS to pin 5 of JP2 connector. Push the HV red knob on the panel. Most of leds will lit on the Ip/HV bargraph.
We calibrate the HV meter with P1 poti later when the unit in the PA: Have to set the P1 up to full scale(3KV)

d./ Ig1 grid 1 current bargraph
Set the small PS to +1.5V out and connect it to pin 5 of JP2 connector. About full leds will lit on the Ig1 bargraph now. Reduce the input voltage set up to first red led position.
Now we will set the G1 current protection level to 350mA: Set up  please the P7 poti up when the D67 inner led indicator start to lit.
The G1 red fault led will blink also. The Ig1 current protection set is ready now. (On case small PA's we can set the overload level to
smaller current level than 350mA. Set for 200mA for single GI7B or GI46B PA's.)
We can calibrate the Ig1 meter with P3(Ig1) poti on UCU-01 unit.

e./ TMP or Ig2 current bargraph
This bargraph has two functions: sign TMP (out air temperature) on case triode PA's, or G2 current level by tetrode amplifiers.
If the display unit is used to tetrode PA's the resistor R22 is built in(120k) and the panel jumper below of pins 6-7 of U9 LM324 IC
is open. This jumper is ON on case triode PA's the R22 is missing.
Sets of triode PA's TMP:
Set 2.3V on our small PS and connect it to pin 2 of JP1 connector. Push please the TMP knob on the display unit. Most of led's will indicate on TMP bargraph.
Reduce the input level up to first red led(75C). Set now the temperature overload level with P3 poti on display unit. The D65 small indicator led will sign the OVR limit. Set fine the P3 to 75C proper overload limit.
Sets of tetrode PA's IG2 current:
We need negative input voltage to check the Ig2 bargraph. So please change the outputs of our small test PS: please put the positive output to the ground. Set  -1.5V output voltage with the poti and connect it to pin 2 of JP2 connector. Push the IG2 black knob on the display unit. Some leds will lit on the IG2 bargraph. Set it up to recommended max. Ig2 current level. (35mA for example on case GU74B and GS23B tetrode amplifiers.)
Set now the overload limit with P3 poti on the display unit. We can calibrate of bargraph sensitivity by P6 poti. The D65 on panel will indicate when we have the necessary overload limit.

f./ Ip current bargraph
Finally we will set up the Ip bargraph meter.
We will give  -9V input voltage to pin 3 of JP2 connector. Most of leds will lit. We can set the sensitivity of the Ip bargraph with P5 poti
on the display unit. We can calibrate the Ip meter also with P5.
  We can set full leds sign with the PS poti. Set now the 1A overcurrent limit with P8 poti on the display unit. The D66 small led will indicate it.

3. MODIFICATION on the display unit
We put on few additional wire shortcuts on the PCB. We built in 5.6V bipolar supressor on place C30 capacitor. No more modification is necessary.





4. FUNCTION and VOLTAGES of display unit connectors.

JP1 CONNECTOR

 JP2 CONNECTOR

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