Friday, March 25, 2011

Bi-directional Amplifier Design

Well it's been a while since I ripped on the ARRL. And since they are doing such a great job, you knew it wouldn't be long before you'd see something so non-professional (amateur) from me again.

from kb9mwr@q...
to w9gig@a...
cc n4qx@a..., n7hpr@t...
date Sun, Jan 16, 2011 at 9:52 PM
subject bi-directional amplifier design help


I'd like to help encourage the development/documentation of a bi-directional amplifier for high-speed multi-media applications.

I was prompted when I read the ARRL Homebrew Challenge I said to myself, why encourage something that has already been done.

Since there are more non-part 15 overlapping channels on 3 GHz, 5 GHz and 900 MHz bands I would encourage it to be for either of those bands.

I haven't been able to make much head way in this myself due to a lack of access to the necessary development equipment.

In some of the open source development efforts that I have been part of, a bounty is often posted as a reward for something like this.

I'd like to take the same approach to this, as I am offering $40 to anyone who can document such a design in QEX or the like. I'd also like to suggest that anyone else interested in the development also consider a contribution to the bounty (aka up-the-ante).

The total bounty-pledges of course will help who ever steps forward in their design and development costs.

To clarify, I am not requesting production or kits, just someone who wants the challenge and has the know-how to create a working prototype and will openly document their design in QEX or some other publication.

Would it be possible to get a blurb in QEX magazine to spread the idea out to the more technical crowd?

Steve, KB9MWR

Yeah, you guessed it, zero replies to my request.

And now some commentary on the HR 607 bill that has provisions to auction off a portion of the 70cm band.

I did my part and wrote to my representatives. While it would be a shame to lose this band, the lower half of the band is Very inactive. Around here the only part used for the most-part is 440-450 MHz.

The current band-plan that caves out the lower portion of the band for ATV and isn't bringing any real traffic/ use either.

Seems a shame that we can't setup a decent wireless (emergency) network, other than this pathetic Winlink business. Heck if we can't do it, sounds like that is exactly what the proposed Department of Homeland Security First Responder network is.

Time to move forward, else I have little desire to continue to write letters to try and defend spectrum that will just sit idle as it has been. Use it or lose it..... maybe the ARRL, TAPR and other "leaders" will one day realize they need to step forward and suggest some new ideas for the hobby to help not only "protect" the spectrum, but put it to actual use.

What I am reading is "When All Else Fails" ... we will build our own wireless network. Possibly a wake up call for ham radio?


N8HM said...

There's plenty of activity on satellites, ATV, and SSB on 420MHz-440MHz.

Maybe its not in sue everywhere, but it is used and is an important piece of spectrum for those uses.

Jim said...

Here in Kentucky we are setting up a digital communications network. We are using BPQ32. It has BBS, Winlink and Chat capabilities. We are also using HSMM to support this project. We are using 2.4Ghz and also using HSMM-Mesh software. Don't give up, take a break and come back stronger. It is always harder for the flag bearer. We need to band together and keep the faith.


Ken said...

I think that dynamic range may be an issue for broadband on 420. The cards that do it have a front end that swallows up 30 MHz of the band. Based on another posting here for the Xagyl 900 MHz unit, it looks like you need to keep all the signals in that range below -70 dBm in order to avoid de-sensing the OFDM card. Is that even possible (on a hilltop location)?