Why you need a low pass filter when using a splatter box amplifier

[loosecannon]

soooo weird.

i see that there is a new post in this old thread, but when i click on it, there's nothing there!

OH WAIT!

It's because i blocked that troll a long time ago LOL.

I wonder what it's like to continually hang around in a place where no one likes you.
LC

 

[LeapFrog]

Gee, I wonder why he deleted the video?

 

[rabbiporkchop]

What's mean about reality? I never thought there was anything mean about having an honest conversation or expecting people to have integrity.

 

[rabbiporkchop]

I wonder what it's like to continually hang around in a place where no one likes you.
LC

Since I'm not the one with the Integrity problem I'm not too concerned about whether or not people without Integrity like me or not I simply point out the lack of integrity and let the chips fall where they may.

 

[LeapFrog]

Integrity and reality, these words sound real good.

 

[Handy Andy]

 

[HARDROCK]

I am with Tom w8ji below why would a low pass filter be needed ?



8JI Ham Member QRZ Page
G0HZU said: ↑
A good quality lowpass filter would be a useful thing to fit just before your inline power meter assuming you are using a typical Ham power meter.

By Ham power meter I mean anything from the typical low cost meters up to and including the Bird 43.
These meters aren't 'proper' power meters and will give inaccurate readings if your radio (or high power amplifier) is kicking out highish harmonic levels.
A low pass filter will not change a thing at the power meter so far as any "harmonics" changing meter readings.

These days, if you are using properly designed stuff and not trying to use unfiltered CB garbage, the worse case harmonics or spurious at 46-60 or more dB down. That means for every 1000 watts, the harmonic power is 0.025 watts or less. Removing .025 watts or much less from a 1000 watt signal will not change a meter reading.

I can't think of any good reason to use a low-pass these days.

73 Tom

 

[HARDROCK]

His testing is flawed. Please see the thread below.

https://www.worldwidedx.com/threads...harmonic-at-2-watts-input.226864/#post-618039

Yes it is Flawed . I specifically ask Mike why he did not check the kl7405v I sent him with the Pearce simpson radio ..
I sent the kl7405v that has regulated ab bias along with the pearce simpson radio so he could match the radio up to the amp.
Which he did as I ask. The kl 7405v has 2 mrf 455 transistors.
The amp has a 20 watt carrier and 80 pep a 4.1 clean ratio.

But my Point of sending it to him was to see what it looked like on the spectrum analyzer.

I asked him what it looked like on the spectrum analyzer, he said I needed to run a Low pass filter.

I emailed him back and told him , You missed the Whole Point. This is what the Public needs to see !!!

Like Mark at Fine tune states , IF they don't show it
they are stroking you !!!

 

[rabbiporkchop]

Integrity and reality, these words sound real good.

Kind of like wabi-sabi on this state-of-the-art sophisticated rf test bench? It would be really interesting to hear what it sounds like in the real world over the airwaves.

 

[TheRealPorkchop]

LeapFrog,
Looks like you got one of them fatal attractions...

 

[rabbiporkchop]

LeapFrog,
Looks like you got one of them fatal attractions...
View attachment 27102

There's nothing attractive about something unproven in the real world. Quite the opposite actually.

 

[TheRealPorkchop]

There's nothing attractive about something unproven in the real world. Quite the opposite actually.

Has nothing to do with what I said.

 

[LeapFrog]

It would be really interesting to hear what it sounds like in the real world over the airwaves.

You won't hear it on the airwaves, it's a modified CB radio, it will only ever operate on a dummy load.

I don't have anything to prove to you, my lab doesn't need to be sophisticated for me to follow regulations.

*Cough Cough*
You wouldn't want to draw Ire for shipping modified gear that can operate on 27 & 28 MHz to truckers, not to licensed Hams, big brother would frown upon that.

Also the Wabi-Sabi for me may never be fully realized, I am still trying new audio amplifiers, new pre-amp circuit configurations, and modulator configuration adjustments, besides the spirit of the Wabi-Sabi is the incomplete, or imperfect state, along with asymmetry at it's heart.

 

[LeapFrog]

sophisticated rf test bench?

Here I demonstrate a fake 50 Watts Peak, from a FQP13n10 MosFet modified TRC-427 @ 14.8 Volts, this was still using the weak TA7222, with this audio amplifier, I don't expect to see an honest 40-50 Watt, 100% modulation, distortion free sine wave, the audio amp is just too underpowered to fully modulate the amount of carrier being produced.
Nevermind the dismal, 29 LTD modulation transformer.


Test Setup:
Tektronix 2336YA 'Scope, Direct sampling RF output through 10X probe.
Bird 43 meter, 50 Watts 2-30 MHz Element.
Bird 43 meter, 10 Watts 25-60 MHz Element, w/ aftermarket Peak Kit.
50 Ohm Cantenna RF Dummy Load
Two 50 Ohm 3 foot coax jumpers
RTL-SDR USB Dongle on Windows 7
for "Band-Scope" + Audio Demodulation.
Craftsman Digital Multi-Meter reading DC input Voltage.

This is a very sophisticated stuffs here, scot, XD
How'do you like 'em apples?

 

[TheRealPorkchop]

Here I demonstrate a fake 50 Watts Peak, from a FQP13n10 MosFet modified TRC-427 @ 14.8 Volts, this was still using the weak TA7222, with this audio amplifier, I don't expect to see an honest 40-50 Watt, 100% modulation, distortion free sine wave, the audio amp is just too underpowered to fully modulate the amount of carrier being produced.
Nevermind the dismal, 29 LTD modulation transformer.


Test Setup:
Tektronix 2336YA 'Scope, Direct sampling RF output through 10X probe.
Bird 43 meter, 50 Watts 2-30 MHz Element.
Bird 43 meter, 10 Watts 25-60 MHz Element, w/ aftermarket Peak Kit.
50 Ohm Cantenna RF Dummy Load
Two 50 Ohm 3 foot coax jumpers
RTL-SDR USB Dongle on Windows 7
for "Band-Scope" + Audio Demodulation.
Craftsman Digital Multi-Meter reading DC input Voltage.

This is a very sophisticated stuffs here, scot, XD
How'do you like 'em apples?