Not sure what is going on, but I took the 590SG to the cabin and it is not properly driving the ALS-600.

Connection is per the manual with a cable bringing two RCA connectors, one for ALC and one for relay, to the amp.

The amp senses the TX connection, because the XMT light comes on when the radio is TX, but there is no amplification, the input power and output power of the amp are the same.

If I connect a spare RCA to RCA cable to the RELAY connection on the amp and short the other end, the amp switches the XMT light on AND amplifies as it should.

If I put an ohm meter on the relay RCA from the 590SG, it shows that tip and ring go to 0 ohms when the radio is TX.

All devices are grounded.

I'm stumped.  I guess I will make a small adapter with a 12V signal relay fed off the 12V from the amp and see if that works.

Do you have the TS-590's menu set to activate the HF relay?  Menu setting #53 I think??

Any chance the ALC adjustment on the back got turned all the way down?  What happens if you leave the ALC line off?

Nick

I tried no ALC connection also.

It's menu 59, and yes.

As I said, the RCA cable end that plugs into the ALS shows a short when the radio TX and the amp does show transmit, it just doesn't amplify.

I have the 590 and ALS-600 but gave up trying to use ALC, the instructions are so confusing to me I feel like I am reading another language. I have just used the relay and regulated the power output of the 590 to drive the amp.

Jim - Signal_20

Can you plug a SWR/Power Out meter between the radio and the amp? Does it read anything? What power level and SWR do you read on the radio's display?
Can you hear the main relay clicking inside the amp when you press Transmit (PTT) button? I assume your amp has a clicking relay (not vacuum type), like the older models.
I'm not familiar with the radio but make sure you have EXTERNAL antenna tuner selected in the TS590 menu.

BTW, the amp has a sourcing input for PTT, meaning that the input is grounded by your radio to switch the amp to transmit mode. You can do this manually with a jumper between the center pin and the outer ring (shield/ground) of the connector.

I have an older ALS-600 in the shack. Let me know if you want me to check anything on my end. I have not used it in the last 2 years, since I bought a new Acom-1000. I probably need to sell it.

It will be a while before I can do any more testing, as the gear is all at my cabin and I won't be up there again for at least a few weeks.

At this point I have to assume there is a ground issue or else the 590 output simply can't draw enough current to make the ALS happy.  So I plan to make an interface with a small signal relay.  I will power the coil from the 12V aux on the ALS and use the contact from the radio to switch that, then just feed a dry contact from that relay to the ALS relay input connector.

ALS is not a relay. It's an analog type output on the amp that tells the radio to reduce power. Usually it does very little but slightly clip the peaks. The ALS knob on the amp. should be set to about 3.
You can disconnect ALS completely and try running without it, just don't drive the amp with full 100 Watts. The amp should produce nearly full power with ALS cable completely disconnected.
Hope this helps some.

Do this before you build a contraption with an additional relay. Pull the TX GND cable out of the radio and short the center and the outer ring of the connector. This should switch the amp to TRANSMIT and the internal relay should click. If it does, look at poor connection on the radio's side or a faulty or improperly programmed TX GND output in the radio. Check the cable with a multimeter too. If the relay does not click, check the cable. If the TX GND cable is good, your amp has a fault and will require a surgery.

Yep, done done and done.

I will build the 'contraption' as a failsafe if all other attempts fail the next time I am able to operate the equipment, as it is clear it operates fine if fed a dry contact closure.  The amp DID have a grounding issue between the power supply and the amp itself.  I tore the amp apart and found and repaired the connection issue.  I suppose it is possible that funkadelic cable has other issues.

I appreciate your help.

Be careful if you operate CW with full QSK. The additional interposing relay may cause timing issues.
A cheap RCA stereo cable works great  for both ALC and TX GND.

Good luck! Hope I did not offend you by writing all this. I just enjoy helping people. This hobby offers a lot to learn, no matter how much experience we have.

P.S. I wonder how much an older ALS-600 will sell for? I need to clean up my shack. There is too much stuff in there that has not been used in a long time. I tend to be a hoarder thou.

No offense taken, every suggestion has the potential to be the one that identifies the problem.

Yes, my hoard of RCA cables from old CD/DVD players came in handy for amp connections.  On the 590SG though, they do not have the standard RCA out connectors for the amp connections, and you have to make a cable to do this using a connector they supply with the radio and your own RCA cables.  I made that cable and it worked fine for the KPA500, but the ALS-600 does not like it.  It shorts though, so I am still blaming the amp.

I bought my ALS-600 off of a member here for $700 IIRC.

Have you done a AD5X relay upgrade to eliminate the noisy relay inside the amp?

Nope!