[TenTec] Update: Hercules II 9420 power on

[k6jek]

You can  turn the power supply on from the four-pin transceiver connector on the back, all the power, not just the power for a transceiver as some have suggested. A small load from pin 3 to pin 1 will do it. I used a 1.2K resistor. 

However, powering up the supply isn't enough to turn the amp on. The switch on the amp must be ON. Half of that switch turns on the power supply but the other half engages the amp keying circuit. Even though it's got the juice from the power supply, the amp won't do anything unless that switch is ON. 

That's a conundrum isn't it? The amp must be ON already if we want to use this remote on capability to turn it on.  This can be solved by opening the POWER ON line from the amp to the power supply. Then the switch could be ON but only half mean it. This would be easy for me to do since I had to build a short extension for that 12 conductor cable. I could put a switch in the wire going to pin 3. But I'm giving up this approach. It's just fighting me too much. I may just build a 220V relay box for the power cord.

Some have asked what I'm trying to do. I sometimes use my OMNI VII remote over the Internet. I turn it on an off via a phone controlled switch. Wouldn't it be great to be able to turn the amp on too?


> I would like to turn on the 9420 and Hercules II from the 4 pin transceiver connector on the 9420. I've seen older posts but didn't quite get an answer or at least I couldn't figure it out.
> 
> According to the power supply (9420) manual page 3-7 second paragraph:
> 
> "... This voltage is used to pull in the main power on relays, K1 and K2, by one of two methods. When the 420 amplifier is switched on +15 VDC is routed back down the amplifier power cable to J7 and on to Q7, the relay switching transistor. Q7 pulls in the main power-on relays and powers up the four high current regulators. Alternatively, the amplifier can be off and and if a load is connected to the POWER ON pin of the TRANSCEIVER CONNECTOR (pin 3), Q7 will be biased on and will provide the power-on signal to Q7. In this way the supply can detect when a transceiver has been turned on and will automatically power itself up"
> 
> I did not hook up a transceiver. I faked it with a resistor to present a load, a 1.2K then a 600 ohm, pin 3 to pin 1. Sure enough relays clicked. The power supply hummed. The Hercules II did not power up.
> 
> There is confusion about the pin numbers: 
> 
> Silk screened on amplifier and FIGURE 2-2 in the manual:
> 
> 	1: GND
> 	2: PWR ON
> 	3: +13.5V LO
> 	4: +13.5V 20A
> 
> Schematic:
> 
> 	1: XCVR PWR (HI I)
> 	2: XCVR PWR (LO I)
> 	3: Power ON
> 	4: XCVR GND
> 
> Text
> 
> 	POWER ON (pin 3)
> 
> Two have it one way. Two have it the other way.
> 
> Any help would be greatly appreciated.
> 
> 
> 
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