On 22 Oct 2023, at 2:30 pm, Adrian Fewster <vk4tux@...> wrote:

?

The thing with LDMOS is to run the voltage a bit lower at higher current. This is way more thermally efficient.

Most of the first 50% rated current draw is wasted on heat, and the rest then adds to RF % as you raise current further?

with lower voltage for same power as higher voltage with less current (hotter).

On a single LDMOS SPE it can be run in low, up to 800w, much cooler than the same in Mid or Max power profile.

Also in Low the LDMOS will survive antenna/coax? failures swr events etc,? much better, than in Mid/Max.

Keep max temperature 50 deg C for a nice long device life. The SPE is an auto antenna switch and also via node-red?

can control the FTDX101MP drive. via node link out/link in ;

function node ;

"

This function node allows a user of this flow to define the drive
power for an exciter based on band and power level (low, middle
and high) much like the way the SPE controls the power level of
a FlexRadio via the CAT port.

The drive levels in the table below are fictional and provided to
test the flow itself. The values must be updated to reflect the
correct drive level for your exciter and amplifier combination.

The "link out" node that follows this node in the flow must be
coupled to a "link in" node in your radio's flow.

*/

var mode = msg.payload.col3
var band = msg.payload.col7;
var pwr_level = msg.payload.col10;
var drive_pwr=0;
var slmh_index;
var slmh_string="SLMH";

/*
The drive power table is unit-agnostic and must be configured for
the units expected by your exciter (e.g., watts, percentage,
fractional value, etc.)

Sample drive power table is configured for:
??? Standby drive power: 100
??? Drive power for???? Low power setting: 1 (all bands)
??? Drive power for? Middle power setting: 2 (all bands)
??? Drive power for Maximum power setting: 3 (all bands)
*/

"
var drive_pwr_table = [

//??? Standby?? Low??? Middle? High
??? [? 5?? ,?? 5? ,?? 12?? ,?? 12],? //160M
??? [? 5?? ,?? 5? ,?? 12?? ,?? 12],? //80M
??? [? 5?? ,?? 5? ,?? 12?? ,?? 12],? //60M (US 5W PEP ERP Max)
??? [? 5?? ,?? 5? ,?? 12?? ,?? 12],? //40M
??? [? 5?? ,?? 5? ,?? 12?? ,?? 12],? //30M (US 200W PEP Max)
??? [? 5?? ,?? 5? ,?? 12?? ,?? 12],? //20M
??? [? 5?? ,?? 5? ,?? 12?? ,?? 12],? //17M
??? [? 5?? ,?? 6? ,?? 12?? ,?? 12],? //15M
??? [? 5?? ,?? 5? ,?? 12?? ,?? 12],? //12M
??? [? 5?? ,?? 5? ,?? 12?? ,?? 12],? //10M
??? [? 5?? ,?? 5? ,?? 14?? ,?? 12],? // 6M
??? [? 5?? ,?? 5? ,?? 12?? ,?? 12],? // 4M
];

/*Note regarding parseInt:
The value to parse. If this argument is not a string, then it is
converted to one using the ToString abstract operation.
*/

band_index = parseInt(band,10);

switch (mode) {
??? case "S":
??????? slmh_index = slmh_string.indexOf("S");
??????? break;
??? case "O":
??????? slmh_index = slmh_string.indexOf(pwr_level);
??????? break;
??? default:
??????? slmh_index = -1;? //infaclid mode returned, flag for zero power
??????? break;
}


if (slmh_index >= 0) {
??? drive_pwr = drive_pwr_table[band_index][slmh_index];
??? }
else {
??? drive_pwr = 0;
??? }

msg.payload = drive_pwr;

return msg;

SPE

<HjQZttX3uTJtL460.png>

FTDX101MP (hamlib flow with rigctld server)

<0BLV09EvuVe03l1z.png>

<jKa0HKh80wIGWwyl.png>

<9mQvCI2bQMe6s24r.png>

73

vk4tux

Run at 1/3 rated power.

On 22/10/23 15:41, John Sparkes via groups.io wrote:

Thanks very much, Adrian !

I have one of those new-fangled SS amps - a 2.5kW PEP out unit from Onder at VK-AMPS. Very nice on CW and SSB, but it doesn’t have the ability to run decent power out on digital modes, so I stick with my DX-2SP for that.

Perhaps I need to by a couple more and combine the output, broadcast style !

Cheers and thanks again,

John VK6JX?