Early RF error only on first transmission same for High SWR

W2PP

David:

I am using an FTDX101D and an ICOM 7851

  I am using the most recent firmware and read the release notes. I had previously observed the High SWR error upon the first transmission on any band, fairly regularly but not always. The second and subsequent transmissions were never a problem. I also noticed that sometimes upon changing bands there were no signals present on the transceiver until I keyed the radio and then they popped in.

Now, with the newest firmware, I routinely see the Early RF, which is NOT the case in real world. I have a 200 ms delay on FT8 and yet see this, again ONLY on the first transmission and then never again. One time I saw both the early RF error and the High SWR error blink across the screen.

I wonder if there is some relay that isn't changing state properly on the first transmision but thereafter is just fine?

David Decoons, wo2x

Which radio are you seeing it on?

The FTdx101D has a CW delay adjustment that affects all modes. Set it to 30 or 40 ms.

The WSJT-X delay will not solve it

Dave wo2x

W2PP

Seeing it on both radio’s. I’ll look I didn’t see an adjustment but I’ll look under CW.

Peter

KD0RC

Is this a problem where the amp and/or tuner is not seeing the frequency from the radio, and therefore goes thru a tune cycle the first time it sees some RF?

W2PP

No amp is rock solid in detecting the frequency of the radio.

I just looked under CW metrics on the FTDX101D and find no place to adjust RF delay.

peter

W2PP

I just changed the WSK time from 19 ms to the max of 30 md. Now that should not have impacted semi break in but it seems to have helped.

I wouldn’t have thought to make that change but glad you recommended it

Peter

KD0RC

Hi Peter, what I meant is the radio passing the transmit frequency to the amp via CAT (over RS-232 or USB)?

If not, then I think that explains why the first transmission has a problem. The amp and tuner have to detect the presence of RF, count it and re-tune. Once that is accomplished, all of the relays are where they need to be, so subsequent transmissions are OK.

W2PP

Thanks but I did understand you a OK. When I changed the QSK delay, a rather odd, unique and utterly unexpected metric that needed to be extended, the problems are resolved. Had Dave not drawn my attention to that metric I never ever would have thought it would have anything to do with SEMI bk in CW or FT8. Probably a bug in the Yaesu firmware. Nice to see things working properly. The PGXL has and continues to be a superb performer. The ETO of modern amps!!!

Peter

David Decoons, wo2x

Not a bug. Yaesu actually documents it affects all modes.

Now to find equivalent on the 7851.

73

Dave wo2x

W2PP

I’ll fix it. I know where it is

thanks Dave

W2PP

OK I spoke to soon.

Same deal, RF early, again ONLY on the first transmission. That this happens ONLY on the first transmission to me suggests something else is at play here. Further, if this really was a situation in which RF was going to soon, then the error should happen every time or nearly every time in the edge case. Instead the early RF is ONLY on the first transmission.

Again this is the FTDX101D QSK set for 30 ms

Peter

David Decoons, wo2x

First, open a Help Desk ticket.

Second, try putting your PG XL fans in contest mode. When in standard mode the bias turns off after 2 minutes on no TX. Contest mode will keep the bias on, cutting down on time for amp to get ready.

Dave wo2x

W2PP

Will do

W2PP

Alright, before I go to a help desk ticket let me try contest mode for a few days. I see what your talking about. I noticed the bias current in the latest firmware was cut from 4 ampts to 2 amps. Easier on the electric bill!

Peter

David Decoons, wo2x

Hi Peter

Bias I’m SSB and AM is always 4 amps (Class AAB)

Bias in single tone mode such as CW and FT8 is 2 amps (class AB) when MEffA is enabled.

MEffA requires a little more drive power in single tone modes but VDD and ID are optimized for maximum efficiency (less waste heat).

If your amp in AABbmode is only doing 2 amps bias, open a Help Desk ticket immediately.

73 Dave wo2x

W2PP

No I’m ok. Bias is appropriate for the modes. Checked out all of them

Peter