View Full Version : Mirage 6 meter amp RF switching mod
11-08-2013, 07:14 AM
Just bought a new Mirage 6 meter amp and there was a warning stating not to operate the amp until the RF switching mod had been completed. Can anyone explain this.
11-08-2013, 07:35 AM
This is from the manual for the Mirage A-1015-G which currently is the only six meter amplifier offered by Mirage.
DO NOT connect this amplifier to a radio without connecting an external control line for the internal relays. If the pre-amplifer is turned
on, and transmitter power is applied without an external relay control
line, pre-amplifier will be damaged
Simply stated the relay switching for the amplifier needs to be the amplifier switching from the exciter.
When you push the PTT the exciter usually closes a set of contacts that will key the amplifier.
The 1015 has a phono jack on the back and when you place a short between the outside shield lead and the inside center conductor this will place the amplifier in transmit.
If you don't do this then if you have the preamp "On" the exciter will send it's power through the preamp and destroy it. If you don't have the preamp on then the power will just pass through to the antenna.
If your amplifier is not the 1015 then you may need to look into the keying circuit for it and find a way to
bring in an external key from the exciter.
Your exciter usually has this provision built in. Unless you've obtained something that doesn't have that (you'd think I'd know that by now:rolleyes:).
So, what exciter are you using?
Does it have an accessory or remote connector that has an external amplifier key capacity?
Let us know what you have and there's bound to be someone here on QRZ that can give you exact instruction.
Hope this helps
11-08-2013, 04:48 PM
The A1015's I've owned and used (last one purchased about ten years ago) actually have an RF activated switching circuit installed, but disabled because that's not allowed by Part 97 based on the amplifier's characteristics. It's lawful for an amateur to modify the amp to enable the RF COS (carrier operated switch), but they can't ship it that way.
You have to open up the amplifier and observe the PCB, and add a connection. I haven't done this in many years, but I think in my last A1015 I had to add a coupling capacitor installed in two "empty" component holes in the PCB to enable the COS operation.
However, if you call Mirage on the telephone and ask, the "routine" used to be they'd ask for a copy of your amateur radio license (which you can FAX to them, etc) and then they'd send you the exact instructions.
Otherwise, the "hard key" line as discussed above by Gary always works and can be found as an available "key line" connection from almost any kind of SSB 6m rig -- but most "FM only" rigs don't have anything like that.