Low Pass Filter For SWL?

[ridgescan]

I went to Ham Radio Outlet in Oakland today to buy some stuff and I asked the guy there if they made a filter to improve hiss on weaker HF signals and I was clear on telling him I wanted this for SWL. He sold me a Bencher 1.8-30 mHz low pass filter. I get it home and the instructions say it is designed for RFI YOU cause from an HF transmitter.
I hook it up and see no really noticable change, except I think slightly cleaner ssb. Is this thing effective for receive too? Or did HRO rook me?

 

[prcguy]

I suppose if you lived really close to an FM or TV broadcast tower the filter might reduce Intermod in a low cost SW receiver, otherwise it doesn't have a use for SWL. I think you probably know more about the equipment than the HRO selesman.
prcguy

 

[barefootdipole]

Yup. thats HRO for ya..the big boys are all about their bottom line....see if you can get it refunded...

you might wanna try an external DSP filter on your RX....or an old fashioned preselector...but the DSP will narrow RX bandwidth to improve S/N ratio so that you hear less noise and more intelligence.....

 

[ridgescan]

Thanks for the info-hey I realize times are tough but it aint cool to sell me something I absolutely have no use for.

 

[E-Man]

I use a West Mountain Radio CLRdsp, while not cheap it makes a world of difference for my location. In fact I could not go back now with out it.

West Mountain Radio - CLRdsp ClearSpeech® DSP Noise Reduction Processor

 

[ridgescan]

Hey Eman-I bought something similar to that 2 years ago-the SCG ADSP2 dsp speaker for like $160 and it sets in the radio closet collecting dust cause I couldn't take the awful tinny pixilated audio of this particular one.
I did a comparison this am between signals with/without that Bencher, and it does eliminate a very small portion of high hiss and it did improve ssb a tiny bit so I guess I'll keep it. I just wanted to further improve what I already have with good grounding and that Faraday deal, and even small increments of noise elimination are always welcome here. $100 though-ouch!

 

[E-Man]

Great! I am not familar with those units, but I am glad to hear it is helping lower the noise.

Edit: Nice Shack Photos!

 

[Turbo68]

Hi Ridgescan i use a Bhi NES10-MK2 dsp speaker its not cheap but it does an excellent job when monitoring weak signals,i actually prefer the bhi speaker than the dsp on the Icom-R75..

Regards Lino..

 

[k9rzz]

You can do amazing clean ups of recorded idents with audio manipulation software. Remove hiss, boost the voices, almost eliminate static crashes. It ain't live, but you can listen to it over and over. Good at pulling out idents when you miss 'em the first time around.

 

[majoco]

The real use for the low-pass filter is to allow your 400watt PEP transmitter to radiate properly, but the filter blocks any slight (hopefully!) radiation from harmonics or over-driving getting into your neighbours TV or VHF radio. A well-designed filter will have minimum insertion loss at HF up to 30MHz and hopefully will have good attenuation at 45MHz, the old TV Channel 1 (or 0 depending on where you live.) Now that most TV broadcasts are UHF and going digital it's probably of no use - to you as a SWL'er or a Ham transmitter!

Oh, and you can download some free DSP software - just feed your line level audio in and you can see and hear all the adjustments.

DSP-Filter - MM HamSoft

 

[ridgescan]

Thanks all for the info

 

[prcguy]

Or you can get a basic model Elecraft K3 and enjoy the best receiver performance and DSP noise reduction I have ever used.
prcguy

 

[ridgescan]

That's a real nice one. And EHam has it 4.9 out of 5 on 168 reviews. Enjoy your toy prcguy

 

[prcguy]

Thanks! I've had it for awhile but my Elecraft KX3 shipped today and will be here next week. That has similar performance but in a handheld package.
prcguy

That's a real nice one. And EHam has it 4.9 out of 5 on 168 reviews. Enjoy your toy prcguy

 

[elk2370bruce]

I'm in the process of saving up for a KX3 to put with my icom 756 pro2. Good luck with your rig and enjoy the outstanding performance the ratings give it.

 

[zz0468]

You might want to try an ANC-4 noise canceller. They're quite effective for locally made noise, and I've also found them to be useful in eliminating a lot of the background hiss on HF. Some of that is galactic in origin, along with other sources, and if it's arriving from one predominant direction, nulling it out can be helpful.

 

[kb2vxa]

Thanks for the warning, looks like HRO has just hit the bottom of the Rat Shack barrel. At HRO you have questions, we have blank stares. Only 10 years ago the Newark, Delaware store was run by hams and WE know you can't stop receiver hiss (a noisy front end) with ANY kind of in line RF filter. Man, you sure pinned my bubble.

 

[ridgescan]

Thanks for the advise zz I have seen that one and may look into it-HRO boss suggested it too.
Sorry Warren-but the hope in this is that Mark the manager there is a longtime ham and is of your school-he has to hold everything together there. The young man I dealt with needs more training and a breifing on not being snarky. Mark is taking care of me by accepting the return and maybe pointing me to an ANC-4 or a preselector.
This filter is helping ssb and a small portion of AM hiss-there must be something affecting me on HF here above the Bencher's rolloff. So it isn't a total loss-without the filter inline, the AM hiss I get on signal fade is pretty harsh-with the filter it's sort of softer lol. Just that tiny improvement makes me almost not want to return it.

 

[lanbergld]

WE know you can't stop receiver hiss (a noisy front end) with ANY kind of in line RF filter.

Correct. A frequency filter has absolutely nothing to do with hiss on sideband. If the user notices less hiss with the LPF its only because of the attenuation of overall signal.


Larry

 

[ridgescan]

Correct. A frequency filter has absolutely nothing to do with hiss on sideband. If the user notices less hiss with the LPF its only because of the attenuation of overall signal.


Larry

Yeah? In that case I will return it and lookat the other options.