PGXL Drive Power SSB

Tom OBoyle

Erika - KØDD

KF4HR

Paul - K6HR

I use the LP-500 with dual couplers that assist in adjustment for linearity (trapezoid display). This really helps keep your signal clean. I had always received good reports, but was surprised to see how non-linear my signal was the first time I connected the LP-500. I now have precise drive levels and evidence that the signal is clean.

Ray - K6LJ

I have the LP-700 as well with the couple as well. This is the way to do it. You can visually see everthing you need to adj properly

Erika - KØDD

W5AP

How do you get   a red PEP bar?   I've never seen it on my PGXL-before or after upgrading to the latest PGXL utility software.    I need to set the 6600M to about 60 watts or more to get 1500 W out of the amp in cw key down.?? 

Erika - KØDD

I dont own one, I just have a ton of amplifier and transmitter experience in both HR and Commercial BC applications. I'm hoping to get one whenever. I dont believe the watt meter on the amp reads pep. There is a red section on the scale. So far I read the manual this morning in response to the post. I have a considerable power difference between my 6500 readings and my 100w Bird 43 slug without a pep mod... I'll get 75 out of the ssdr and ddutil, and 85-90 on the watt meter depending on band. So I can't answer why you are seeing higher drive to get 1500 out. I've got high main voltage at our place, theres variables at every level from the cable between the rig and the amp on to the end. This LP-500/700 looks like a nice device... those who actually have the PGXLs are going to need answer the smaller variables at this time. Getting actual drive and swr between amp and rig and power out measured at the output to a dummy load. Then cross reference indicators I apologize for any miss info on the pgxl itself. Sure wish one was sitting here. Erika DD

Ian1

The interesting thing to me is figuring out what works on what bands and what modes. For me I base it on expierence and learning how to use this new to me Amplifier. The other items are AC power in your and this taken from 403a manual. What is MEffA? And when to use MEffA, Mode AB, or Mode AAB. MEffA was invented by 4O3A himself and stands for (Maximum Efficiency Algorithm) and this feature noticeably increases the efficiency of the amplifier when processing constant level tones or non-AM signals, such as CW, RTTY, FM or FT-8 type signals. It works by decreasing the drain Voltage on the amplifier devices, requiring more drive, which moves the amplifier closer to a higher efficiency “Class C” operation. It is only available in “AB” mode. It is not applicable to amplify signals with a varying amplitude, such as SSB, AM, or PSK-31. These modulation modes require the use of Mode “AAB” which provides maximum linearity, but at a lower efficiency than Mode “AB” because you are operating closer to operating the amplifier at Class “A”. Important Note: Though the MEffA box may be checked in the PGXL Windows App, it is active only when the amplifier is in Mode “AB” and has no effect in Mode “AAB”. You can operate in Mode “AB” without MEffA enabled, which still offers mild improvements in amplifier efficiency, especially for constant level signals, relative to maximum amplification linearity. Adjustment of MEffA at a desired power level requires a “tuning” procedure. Key the amplifier with a “Tune” or drive signal, to establish the desired output.Unkey the amplifier then re-key. (You may note that the amplifier drops the Drain Voltage and see the corresponding drop in output level). This is MEffA working.Increase drive to re-establish the desired output level. Then repeat the process (starting with step 2 until the desired output power is achieved for every time keyed.You are now ready to operate. If you don’t want to go through this process, you can leave MEffA off (box unchecked in the PGXL Windows application) and use a fixed drive level that should always correspond to a fixed power output for a given band. Ian Km4cqg

Tom OBoyle

I can get 1500 watts on my Diawa meter with 32 watts of drive on 40m in CW key down.  On the amp utility on the PC it shows about 1250 or so. If I set the drive to 40 watts, I get 1400 on the amp but over the max (beyond 1500) on the Diawa meter.  

I'm no expert at all at amps but I think my results are more consistent with what others have seen.

Tom

Tom OBoyle

Thanks all.  I will look at the LP 500.  Maybe Santa can supply one next year

W5AP

thanks for all the comments

Still looking forward to some software upgrades to improve the amps power output visibility

W5AP

Gary NC3Z

Only difference is screen size, nothing more on the LP.

N2WQ

For the record, MEFFA, aka dynamic bias, has been around for decades.

KF4HR

KF4HR

4O3A Signature

Meffa is not dynamic bias. It controls drain voltage.

N2WQ

Fundamentally, however, it takes the envelope of the input signal to set the output power. No? Commercial use amplifiers have been doing so forever.

KF4HR

4O3A Signature

No. It controlls efficiency ... Modulated power supplies are best but more expensive solution. MEffA is simpler, cheaper, and very effective 73

Sergey KN7K

Hi Ranko,
Since you are monitoring this thread, could you please comment when PGXL Windows SW will be fixed? Flex says it in works but no commitment day yet.
PGXL is out for a while and it is weird that no fixes available yet.
Thanks and Happy New Year!
KN7K

4O3A Signature

First, HNY to all of you. I have few tasks on To Do List and this one of them. We are working on few different solutions for better metering. I expect to have Alpha version in a month. With latency we have over the IP, it is not easy, but it is doable. 73