Showing posts with label power settings. Show all posts
Showing posts with label power settings. Show all posts

23 Dec 2012

FT817 "power blobs" question

Having owned my FT817 (original version, not ND) for nearly 12 years I am almost too embarrassed to ask this question now.
http://upload.wikimedia.org/wikipedia/commons/5/55/Yaesu_FT-817_(1).jpg
When checking an old Bird RF power meter today I measured the power of my FT817 on and off a PSU at all power level settings. All these years I had assumed that "3 blobs" on the screen (when on a PSU) meant that I was putting out 5W. What I measured was closer to 2.5W. This did not change when the PSU was disconnected: still 2.5W. Then I pressed the button to "no blobs" and the power went up several dB, to I assume a nominal 5W. When on batteries it was "blinking 3 blobs". having re-read the FT817 (original) manual I was none the wiser: it does not mention a "no blobs" setting.

I think all these years when I had assumed my DX was being worked with 5W I was actually using just 2.5W. It looks like I should have gone to the "no blobs" setting with a PSU to get the full 5W.

So, can someone please clarify what power the FT817 should produce at all the different "blob" settings on batteries and on a 13.8V PSU?

UPDATE: I have the answer from Pete M3KXZ

Hi Roger.

On PSU:
- no blobs, output is 5W
- 3 blobs, 2.5W
- 2 blobs, 1W
- 1 blob, 0.5W

On internal batteries, the radio will default to "L///" and output 2.5W. If you
select high power, you will get 5W with "///" blinking. The other blobs are same
as for PSU.

I always run off external battery pack and the max power setting shows no blobs,
until the voltage starts to drop a bit when it automatically goes to "///"
blinking.


Well I'll be damned!  So for 12 years nearly I've been running 3dB less than I thought.