11 meter bandpass filter

[86lidewell]

https://surgestop.com/filter-products/m-411cb.html
I ordered one of these the other day. Just wondering if any one had experience with one and if it solved their problem.

Model: M-411CB
Frequncy Range: 26.9-27.4 MHz
Impedance: 50 ohms
Power handling: 200 watts
Connector types: UHF
Uses: Blocks all frequencies above and below the desired band.

 

[sp5it]

I would like to see it's measurement on manufacturer website. So far it's just expensive metal box.

 

[jkp1]

I want one. I have an export for the power, but I could care less about frequencies outside 11 meter.

 

[sp5it]

You know the purpose of bandpass filter and when it's useful?

 

[86lidewell]

for me, it's going to be for testing/reducing SWR between the radio and the amplifier. If it suppresses harmonics and spurs, it will point me to the problem. I already verified the first order harmonic, 54Mhz using a 30 Mhz low pass filter.

 

[86lidewell]

https://www.tinysa.org/wiki/
the filter is a quick and dirty way. This will be more informative.

...Maybe just getting my feet wet with Spectrum Analyzers.

 

[Slowmover]

I’ve posted about the Morgan Systems 411cb Bandpass Filter elsewhere.

Another contributor showed an AA screenshot.

 

[86lidewell]

I’ve posted about the Morgan Systems 411cb Bandpass Filter elsewhere.

Another contributor showed an AA screenshot.

Fact or fiction

 

[jkp1]

You know the purpose of bandpass filter and when it's useful?

You know, I don't. Please educate me.

 

[86lidewell]

You know, I don't. Please educate me.

The way I understand it is unlike a lowpass filter, which in the case of a Drake 30Mhz for example, filters out anything above 30Mhz so it will suppress the 54 Mhz harmonic if there is one. You will see the SWR on your radio higher with the AMP on but the AMP to the antenna may be a perfect match. The 54Mhz harmonic, (multiple of 27Mhz) is causing the the reflection due to the amplifier being tuned to ~27Mhz, certainly not 54Mhz and reflecting power back to the radio/driver.

A bandpass filter filters out everything except the band you are wanting to transmit on. A bandpass filter is used mostly to suppress nearby bleed-over when HAMs are "contesting" and nearby traffic is on different bands are interfering.

 

[Slowmover]

Fact or fiction different thread

Search threads under my screen name and device name.

“CB BANDPASS FILTER” (thread) #30 & 31

.

 

[86lidewell]

CB BANDPASS Filter?

 

[Slowmover]

CB BANDPASS Filter?

thread name. Bumped it for you.

 

[Slowmover]

I would like to see it's measurement on manufacturer website. So far it's just expensive metal box.

All are welcome to put aside my anecdote; at least see the thread mentioned.

 

[86lidewell]

yes thanks. My post above yours is the link to it.