HFU HF Underground
General Category => General Radio Discussion => Topic started by: Skipmuck on June 25, 2017, 1304 UTC
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As it is unlikely I will upgrade from my old school analog NRD-515 anytime soon, I was looking into purchasing one of the BHI products, perhaps the BHI DSPKR. I am plagued with constant local QRN here. I looked at the reviews of both the Heil Clear Sound and the DSPKR and it would seem the better of the two is the BHI as far as noise cancelling to enhance speech. I would be grateful for any hands on insight into these DSP speakers before purchasing one. Your replies would be greatly appreciated!
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I have to deal with a lot of local QRN here also.
When I built my folded dipole for 43m it eliminated about
95% of local noise.
A huge improvement from my longwire
and the regular dipole I used to have up.
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Another vote for folded dipoles vs traditional, much lower in noise. And sky loops are better yet ;D
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I had a 10m folder up about a half wave, and it barely had any noise at all, made me think it wasn't working till the dx started rolling and then I was all like whiskey tango foxtrot so another vote for a noise cancelling antenna rather than a dsp box. However, cleaning up in home noisemakers can go a long way towards getting rid of the worst of the noise, almost always inside your own home. That being said, I've a street light on the corner that has issues, when it flicks off, as it does at times during the night, the hash it releases is like Godzilla vs Mothra in proportion.
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Thanks for the input! I just might put up one of these folded dipoles near the end of the summer hot season. The horizontal half wave I'm using now does seem to pick up more noise than my alternate longwire. But even with that, does a DSP box improve the intelligibility of speech signals with the reduction of natural background noise such as T-storm static, etc? My stock NVA-515 speaker just doesn't cut it. When I run the NRD through my stereo, I get lots of boomy audio that works good for music, but does not help with human speech very well.
At 62, I'm only a few years away from retirement...40 years at a local forge shop has not done my hearing any favors, despite constant use of hearing protection over the years. There seems to be a range of frequencies that I have trouble hearing properly....mostly the range of human speech and the upper frequencies.
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I sympathize, Skip. I spent several years my early 20's working a shift in a machine shop. It was ran by the state and not subject to OSHA regs on hearing protection. The Walkman had just came out, they suggested we buy them for hearing protection! You've got to love the government.
The place was so loud, we could be standing inches apart yelling at the top of our lungs at each other about what we had to do next, and it was still a crap shoot whether we got the info right? We would walk out of that place staggering like drunks due to our equilibrium being messed up by eight hours of the noise.
My wife and I went to a concert about a week ago. The bands were loud in the extreme. She's been complaining about her hearing being off since. Me? The ringing my ears hasn't been this mild in thirty years. I guess I needed a dose of "noise therapy"?
I was looking at a bunch of TV feedline I have the other day and thinking I might try to get a folded dipole up in a few weeks. God knows RF spewing devices are only going to increase in the future.
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I saw a lot of concerts that came through town in the early 2000's and earplugs as far as I was concerned were mandatory. I do like to feel the kick drums, but the rest I can do without, particularly the three day noise hangover. I saw one concert in about 1996 without plugs and my ears were ringing for a week afterwords. I swore I would never do that again.
I usually wear plugs in the x-mobile and sometimes the car on long trips. I feel less fatigued if I do.
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I bought a BHI Compact In-Line Noise Eliminating Module (a bit different to the speaker you're asking about - this one goes between the rx and headphones) and used it extensively for 3 months with a Lowe HF-150 then stopped using it. It cuts down background noise considerably but I don't know that it got me any more dx loggings as a result. What put me off was that out of the 8 (approx) filter levels, the top 5 or so distorted the sound considerably. Sounds like waves gently sloshing around in a cavern. However, I plan to try it again at some stage - I think if I contented myself with using the bottom 3 levels there might be a benefit.
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As to audio dsp systems, they can take a sig in the mud you can't hear and make it mostly understandable, but don't expect much more than that. I've had the Heil and timewave, the Heil did really well at cleaning up the white Gaussian background noise on hf if set to a lower level, it impressed me the most out of the audio systems I've used. I've had dsp in several HAM rigs and dsp noise reduction still hasn't got to the earthshaking level yet, however dsp demodulation and filtering is pretty earthshaking. Other than that it was often a hindrance to otherwise clean signals. Another thing is they might offer a auto notch that really can come in handy at times if your rig doesn't have a notch built in. also hardware audio filters can be of help, the elliptical lowpass audio filter is a fav for swling but I don't have a link to a design handy.
On the folder dipoles, one thing to keep in mind is they don't accept energy at twice their resonance and even harmonics, so they do a good job at filtering the 2nd harmonic if you tx with one. I've often wondered how a off center fed folded dipole (OCFFD) would fare, perhaps a low noise yet multibanded antennae would result.
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Thanks to all who replied to my inquiry! My first choice was going to be the Heil until I saw that some of them had problems. When I was on the BHI website, I did see the that noise cancelling module, but prefer to listen sans headphones. I could never get used to them again after those 1970's UMASS years when one night my trusted and true Koss headphones managed to wrap themselves around my neck. I had been drinking kinda heavy that evening, and the cord left an imprint on my neck that didn't go away for awhile. True! So it would seem that the way to go might be the BHI DSPKR used on the lower settings until I can get the things I need for a folded dipole.
I attended my first concert in the summer of 1970 (The Grassroots!), and that started a long run of maybe 40-50 concerts, mostly during the 70's, but a fair amount in the 90's, with the last one in the early millenium, which fulfilled a lifelong wish to see the Who! I think the loudest was probably Black Sabbath in 1971 in Hartford. That was back in the days when they were still hungry and Ozzy had yet to become a parody of himself. My ears were ringing for a couple days after that one! So I have done quite a job on my hearing over the years....back in the 80's I would spend hours at a time straining through the hets and the noise with the FRG-7....I don't think that helped much either....and then there was the old Pioneer SX-525 with the Advent speakers...not to mention my late brother's 90's grunge band cranking out in the garage.....sooooo, I need a little boost in the speech range of frequencies. The music is no problem, as I have a fairly good database of memories:not to mention the use of Shazam which I use on a regular basis. Again, thanks for the input!
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I dunno, Ozzy seems to be doing pretty good for a guy who has actually been dead.