Pages: [1]   Go Down

Author Topic: AL-1500 24VDC Relay schematic  (Read 134 times)

N3QE

  • Member
  • Posts: 5664
AL-1500 24VDC Relay schematic
« on: March 15, 2023, 05:43:38 AM »

The schematic that came with my AL-1500 and the schematics I find on the internet show +12V being used to throw the antenna relay.

All the AL-1500's (and I think AL-1200's) I've ever met in real life have a modified meter board to use a voltage doubler (caps and diodes), to generate a new +24V supply for the antenna relay. I'm sure there's a different part number for the 24V antenna relay board too. Maybe a couple of these were user mods of early amps, but I'm sure the vast majority came out of the factory to use +24V.

Above voltages are "nominal" really they are substantially higher at least when the relay isn't keyed. I broadly understand the +24V may be in part to speed up the pull-in of the relay; not clear to me whether the +24V is used to sustain relay hold-in.

Is there a schematic or mark-up out there for the 24VDC relay version?
Logged

W1QJ

  • Member
  • Posts: 3344
Re: AL-1500 24VDC Relay schematic
« Reply #1 on: March 15, 2023, 07:33:17 AM »

The new dual encapsulated relay system has been out now almost 10 years.  Since then, the schematics haven’t been upgraded by Ameritron.  The old single 12v relay system schematic is still prevalent.  The only schematic of that board I think may appear at W8 JI webpage.  Check there for it.  The 24v on the new boards do speed up the output relay and has timing on it.  Those relays are good for up to about 35wpm QSK.
Logged

N3QE

  • Member
  • Posts: 5664
Re: AL-1500 24VDC Relay schematic
« Reply #2 on: March 15, 2023, 10:37:44 AM »

Some updates I got via emails on the schematics!

This page of W8JI's describes how the updated relay board uses the +24V line and some transistors/capacitors to speed up and properly time relay pull-in: https://www.w8ji.com/ameritron_relay_module.htm

Page 17 of this manual, the page is labeled "meter board", attempts to illustrate the voltage doubler on the modified meter board but I'm sure it's got a couple omissions/mistakes: https://static.dxengineering.com/global/images/instructions/ame-al-1500.pdf
Logged
Pages: [1]   Go Up