[TenTec] OMNI VII vs. K3 ? Opinions invited.,

[shristov]

Rick - NJ0IP / DJ0IP <Rick at DJ0IP.de> wrote:

> ... this full power into 3:1 SWR


Hi Rick,


"full power into 3:1 SWR" is just a myth.
Did you ever read such a claim made by TenTec?

There is nothing inside TenTec transceivers to make them
to DELIVER full power into a mismatched load.

TenTec transceiver do not DELIVER full power into a mismatched load.
They just fail to reduce the drive with high SWR because they mis such a circuitry.
Consequently, the FORWARD power stays the same, at 100 W.

But we must remeber that:

  DELIVERED power = FORWARD power - REFLECTED power.

Power meters inside Orion, Omni VII, and virtually all the other rigs
display FORWARD, not DELIVERED power.

With SWR = 3, we have:
  FORWARD power = 100 W
  REFLECTED power = 25 W
  DELIVERED power = 75 W

Similarly, with SWR = 10, we would have:
  FORWARD power = 100 W
  REFLECTED power = 67 W
  DELIVERED power = 33 W

The only thing that can make PA deliver full power into a mismatched load is, of couse, a tuner.
TenTec transceivers are no exception.


73,

Sinisa  YT1NT, VE3EA