[amsat-bb] RS-44 VU noise from TX

[Mike Diehl]

See the following response I got from them. Highest power I’ve heard being used on the BLP-200 is 50w. 

> Hello Mike,
> 
> Our BLP, BHP and BBP series of filters are all designed with lumped LC components.
> The capacitors typically have a working voltage of 50-100V, so they aren't a problem with high power.
> 
> The inductors are core and wire based, and we consider them to be limited by when the core saturates.
> For a lowpass filter, this will cause degradation in rejection a high frequency.
> For a high pass filter, this will cause degradation in passband insertion loss.
> The 0.5W max power we state is for higher frequency power, or in your case, the out of band power.
> 
> In terms of the survivability of the unit, 0.5W will not cause any overheating or permanent damage. The limit is there purely for performance issues.
> In order to save time in testing and qualification, we've identified 0.5W as a worst case among the filter series and specify as the max power for all 3 series.
> 
> If you are seeing good performance in passband and rejection at higher powers, that is great.
> Just know that some of our filters may be represented better by the 0.5W max than others.
> 
> Regards,
> William Yu
> Mini-Circuits
> Applications Engineer


73,
Mike Diehl
W8LID/VE6LID

> On May 24, 2020, at 15:53, Steve Kristoff via AMSAT-BB <amsat-bb at amsat.org> wrote:
> 
> 
> I've considered getting Mini-Circuits high and low pass filters to go between my handhelds and my Arrow antenna. But the datasheets for the ones that I looked at only rate the filters at 0.5W. I'd be pushing about 5 W through them. 
> Does anyone here have experience doing that to these filters and can comment on whether that works or not?
> Are there Mini-circuits filters that will handle 5 W comfortably?
> Steve AI9IN
>  
> ----- Original Message -----
> From: Jerry via AMSAT-BB (amsat-bb at amsat.org)
> Date: 05/24/20 14:45
> To: Andy Brian (briaandy at gmail.com)
> Cc: amsat-bb (amsat-bb at amsat.org)
> Subject: Re: [amsat-bb] RS-44 VU noise from TX
> 
> Hoi,
> 
> Instead of putting a diplexer as filter( best is to use 1 per band), if you have the possibilty to make stuff your own, just 'split' a diplexer by making an LPF (low pass filter) at the 2m antenne and a HPF ( high pass filter) at the 70cm antenne. Or find some to buy (MINI CIRCUITS maybe?).
> This way you have a filter at both antennas. Mostly a diplexer is used only on one antenna, while the other diplexer port is closed with a small dummy load.
> Keep in mind the tx-pwr!
> 
> Best 73's
> 
> Jerry,ON4CJQ
> 
> 
> 
> 
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