Apache Labs Community Forum

I can easily hit 100+ watts on all of the other bands but I can only barely reach 85 watts on 12 meters, regardless of any PA Settings. If I try to push more than 85 watts the output power never increases but the PureSignal curves start getting really wonky during phone TX.

The problem exists regardless of whether I'm sending power to the antenna or a dummy load, and the strange PS behavior is regardless of whether I have the bandpass filter enabled or not, and regardless of whether I'm using the internal or external RF sampler.

Any ideas?

Mark

Hi,

Please check whether the correct LPF is selected. At 12m, the 10m LPF should be active. There were devices where the 15m LPF was active, which led to a defect in the LPF. (When switching from 12m to 10m, no relay in the LPF should switch).
Do not attempt to compensate for any errors by significantly raising the driver line.
Which firmware and software version are you using?

Interesting suggestion. I had forgotten about that problem because, IIRC, this was only an issue with Thetis and Protocol 1 firmware because P1 firmware had a feature whereby the firmware could select the LPF instead of Thetis. In Protocol 2 firmware, Thetis has sole control over which LPF is selected.

We'll have to see what firmware Mark says he is using.

LPF is correct, see screenshot below.

Firmware is Protocol 2 (v3.9) Ver 2.2.2. Software is Thetis v2.10.3.12 Release.

My power cable is brand new, Thetis' volt meter only shows a .4 volt drop at 100 watts output on any other band. Thetis' amp meter reads 10.1 amps at 85 watts on 12 meters and 13.9 amps at 100 watts on all other bands.

Mark

Hi, has your rig always showed this issue or in the past on 12 m it was able to deliver around 100 W?
At this point it seems an hardware issue and many components can be involved.

I don't know how long the problem has existed, I've never had a 12 meter capable antenna so I never had any occasion to adjust the PA settings before now. It wasn't until I recently replaced a defective power cable that I felt a need to revisit the PA settings for all the bands.

Mark

Hi, from what you describe could be something hardware on the RF board.
The circuit design is very sensible to inductance and capacitance of PCB lines near the final MOSFETs and the final transformer and it is not simple to adjust components value to find a flat response over the entire HF band.
It is also not easy to access the RF board.
I suggest to accept this small difference on max power in 12 m band.

I do concur that that may be the most stress-free path, lol.

Thanks for the thought.

Mark