At the Hands-On Musuem, we’ve been having some trouble with our signals getting into some cheap computer speakers that one of the staffers has connected to her computer. I Googled to see if I could find any information on this, and came across a reference to some computer speakers that West Mountain Radio sells that are supposedly RFI-resistant.
I e-mailed them, asking if they might be able to tell me what they’d done to improve the performance. Here’s their reply:
Hi Dan,
We are sure you can find a great deal of information in the ARRL Handbook about making equipment, that has to exist in strong RF environments, immune to that RF.
I the case of the computer speakers we designed and have available for sale in our line of quality Amateur Radio Products, we have applied some of these techniques and some of our own. However because we designed these as products in our continuing attempts to remain in business by making a profit (as slim as it may currently be) we do consider this to be Confidential Intellectual Property and as such we are unable to be anymore specific than this.
Thank you for your interest.
Ed K3EIN
Sales & Support
West Mountain Radio
This response really turns me off. I could maybe see them responding this way if I was asking for some super-secret DSP algorithm or something like that, but as K3EIN points out, this information is readily available. It’s certainly not rocket science. Anyway, this makes me kinda not want to buy anything from West Mountain Radio again.
Kelvin says
It does seem a bit stingy. I mean c’mon we’re talking about speakers here. Maybe they lined the speakers with tinfoil and make you wear a silly hat while you use them?
Mike - WM4B says
I don’t know if I see a problem with their response. After all, the guy is trying to make a buck and I can’t believe that his profit margin is that high. After all, what’s to keep someone from asking a question like that and then marketing their own version for a couple bucks less?
Just my 2-cents worth.
Ed says
Unbelievable. I have a brand new West Mountain Radio Rigblaster Plus still in the unopened box. Makes me wonder if I should just return it and go in some other direction based on principle alone? If I have trouble with it, is this the kind of treatment I can expect? Seems to me they could’ve given you a little more information without revealing all of the “secret technologies” they’ve hidden in those $40 speakers, you know?
Martin AA6E says
Easy enough to find out by buying one. On the other hand, I presume their mods are basic filtering — ferrites and all that. Given how cheaply built normal computer speakers are, I expect it wouldn’t take much to improve their RFI tolerance.
Of course, they could have said as much.
73
Martin
Ronny says
Dan:
I know how you probably felt reading that response, but they really are in business to make money. While they could take the “you could build it, but would you” approach and tell you what is inside the speakers, I guess that is like giving out a prized recipe. It may not be rocket science, but it’s their special thing. From the consumer perspective, it stinks to be turned away, though.
Why don’t you turn it around and see if West Mountain Radio will donate a pair of their speakers to the Museum. Then, the burden is on them to show they are a good neighbor in the community. As they are a bit smaller, I wouldn’t completely hold it against them if they said no, but give them the chance. I have found that Icom is extremely helpful to schools. I e-mailed and said we couldn’t find the mic to a radio we found in the closet…done! Got one in the mail a few weeks later.
Good luck with the RF issue.
73,
Ronny, KC5EES
Austin, TX
Rob Carlson says
There’s a cost delta between the time and effort it takes to tinker something into working based on general guidelines, and following specific instructions to replicate the original product. They put in the time and effort and now they want to make a few bucks off each unit they sell to recoup that research effort.
Bobby R says
Not to mention the grammar and spelling mistakes in their letter.
David Brodbeck N8SRE says
This is exactly the sort of mindset that causes companies to leave schematics and repair info out of their manuals.
Dan KB6NU says
Great comments, everyone. Thanks for all the replies.
I do know that they’re in business to make money, but sheesh. As someone mentioned, I could simply buy a pair, reverse-engineer them, and then post the results of my study here, complete with pictures here. I still might do that.
Also, as someone mentioned, if they’d told me what they’d done, I would probably be even more inclined to buy a pair, given the amount of time it would take me to acquire the parts and then apply them to the troublesome speakers. Now, I don’t really know what I’d be getting, now would I?
The comment that I liked the best was to turn this around on them and ask them to donate a set to the museum. I may have already burned that bridge, though. :)
For what it’s worth, I installed a clamp-on ferrite core around the cable connecting the computer to the speaker. A couple of turns seemed to do the job. So, maybe this is a big to-do about nothing. Next time you’re at a hamfest, pick up a handful just in case you ever need them.
David Brodbeck N8SRE says
I’m sure Mike’s right about their motives, but it’s short-sighted.
If you were another company trying to compete with them, it would be a trivial expense for you to buy a pair and reverse-engineer them. Ironically, patenting their methods would have both protected them from that possibility and made the design features public…
Buck (N4PGW) says
Today, every ham has heard of the ferrite beads, W2AU balun and toroid cores, but thirty years ago, the panacea of fixing radios was found in .01 1KV Disc capacitors. We put them everywhere. Across switches, across dc hot to ground, across cw keys and across speaker terminals.
It is possible they could be using the ferrite beads or a capacitor, or maybe an RF choke.
There are a number of things you could try, but I see you found a solution.
73 for now
David Brodbeck N8SRE says
The disc capacitor advice is good, especially for low voltage applications. I found they did wonders to stop RF from getting into and shutting down a PC power supply that I’d converted for 12V rig power, and unlike ferrite beads they’re in everyone’s junkbox.
Mark (K6HX) says
Lots of products that hams buy (and indeed, myself included) are really quite radically overpriced compared to the cost of both engineering them and the parts involved. Consider how many dipole antennas get sold, mostly to avoid the “problem” of properly crimping a couple of connectors. Digital interfaces. Power supply boxes. We pay for convenience.
I think it’s pretty petty to get upset at these guys for trying to protect their business. Heck, he answered your email, that’s more than a lot of small companies would do. He actually did provide you with information that was helpful, just not as helpful as you seemed to think he should have. *Shrug* Asking him to spell out precisely what they do is probably a bit much to ask.
Glad to hear that the ferrites cured the problems. Curing RFI problems is a good skill to learn for all hams.