FT991A Receive Gain Settings IPO - Pre-Amp1 – Pre-Amp2 dB Examples -

I'm sorry no live demo, HF antenna problems as soon as I get HF I'll run some live demos, unfortunately the IPO/Pre-Amp 1 and 2 do not work on 2 m SSB 144.200 which is all I have now 2m/.70cm

This video I taka a review of my understanding of how to interrupt the IPO, Pre-Amp1 and PreAmp2 on the FT991A and how they relate to S units on your recover.

This is not guarantied to be 100% accurate, if there are things that need to be fixed let me know, a lot of this I put together from some very good videos on You Truee on similar subjects and tried to make the relationship to the FT991A.

The base rule I'm starting to see is 6 dB is 1 S unit. This seems to be mentioned and I think this is correct. 6 dB is also (4x) gain in Logs, meaning that if you are hearing a station on your receiver at S3 transmitting at 375 watts and they increase their power to 1500 watts (4x) or 6 dB, you will now be hearing them at a S4.

This is a review of the Pre-Amp feature on the FT991A, and the additional RF (Receive Frequency) gain added when the Pre-Amp is active. The Pre-Amp on the FT991A increases the signal from the other station at a level of 10 dB (Pre-Amp 1) and 20 dB (Pre-Amp 2).

With the Pre-Amp 1 or Pre-Amp 2 active this can increase the other stations signal on your radio receive meter by as much as 3.3 S units. The (RST) Receive Signal report consists of two parts in the voice mode the Receive “R” (which is a scale 1-5) and is how well you can hear the station, the second part is the Signal “S”, the S is what you are seeing on your receive signal meter. The scale can be from 1 to as high as S9 + 20 dB. The last portion is Tone “T” this is for CW and is not used in voice.

Brief review of dB levels when receiving signals:

On your Signal “S” meter, every 6 dB (4x) power increase in the other stations power is 1 S unit on your receiver's signal meter.

From this 6 dB baseline to 1 S unit, we can model the receive S unit change on the FT991A with the dB gain of Pre-Amp 1 and Pre-Amp 2.

If you have a station at S3 and you turn on Pre-Amp1 the S meter will increase 1.67 to 4.67, if you turn on Pre-Amp2 the S meter will increase 3.33 to 6.33

Видео FT991A Receive Gain Settings IPO - Pre-Amp1 – Pre-Amp2 dB Examples - канала West Texas Video Gates (KI5JUF)