ARRL

K8WHB

Joined: Tue, Jan 11th 2011, 19:02 Roles: N/A Moderates: N/A

Latest Topics

Topic Created Posts Views Last Activity
Another new source of RFI on 70CM Jan 29th 2012, 20:26 5 1,747 on 18/6/12

Latest Posts

Topic Author Posted On
Why are cellular bands blocked on receivers? ka9wgn on 29/1/12
Even if the FCC wanted to change those rules they could not do so UNLESS Congress modifies the Telecommunications Act of 1996 to remove the requirement that the FCC promulgate these rules.
Apple patent conflicts with APRS? AB1AW on 29/1/12
This brings up one very BIG failing of the PTO - their review of submitted patents for "prior art" is pitiful. And I say that having a brother-in-law that is a Patent Examiner for the PTO. Apple, Microsoft & numerous others have filed for & have been granted patents for stuff that is plainly "prior art".

The way the patent laws are skewed now days a patent is deemed valid until it is proven invalid. So Apple patents something that is prior art, then sues someone for infringement and that person is going to have to expend the $100K plus to prove the patent invalid. The patent departments of most of these technology companies (and this was actually stated in a book written a few years ago by the former head lawyer of Microsoft, who has a really appropriate last name: Nukem) take the attitude of using patents as an offensive weapon - patent everything in sight, ignore prior art, and just bulldoze anyone that gets in the way. One shining example is Microsoft's patent on the "FAT" file system - the prior art on that goes back to before Microsoft was even a company!!

Somehow I don't think this is what Madison & Franklin had in mind when they placed the patent & copyright clause in the Constitution.
Another new source of RFI on 70CM K8WHB on 29/1/12
Well it looks like the FCC has done it to us again, this time on 70CM. Friday (1/27) Federal Register published the rules for MedRadio devices using segments of the 70CM band.

I read the entire piece and found a couple of interesting items. First, even though they are unlicensed devices, the MedRadio implant devices are given full secondary status, the same status amateur radio has in the 70CM band. Now interestingly, read 95.1211 (c) of those new rules and it says MedRadio devices must cause no harmful interference to and and must accept any interference from, to quote "from authorized stations operating in the 413-419, 426-432, 438-444 and 451-457 MHz bands". Ahhh, but there is more! Read on to 95.1215 (b) & 95.1217 (b) on the disclosure statements & labeling requirements, and the word PRIMARY is added. So it appears we have a conflict here. One place says hams are covered (since we are specifically authorized by license to use 12 MHz of this spectrum {except above "Line A", where we are only allocated 8 MHz}) and the other says we're out in the cold (since hams are not primary users {we got shafted out of our primary status by the DOD and the FCC back in the 1970s}).

The medical people will read the paperwork included with the devices and probably never read 95.1211 (c), so it appears, as far as the meddical community is concerned, we will be stuck having to tolerate any interference we get from these devices AND be left out in the cold if a ham causes interference with one of these devices.

Makes one wonder if the folks at the FCC read this stuff before they send it on to the Superintendent of Documents?
What rigs do you use for AM operation and why do you like using AM? W1RFIAdmin on 19/9/11
Ed, it has been many many moons since I've operated 2M AM - back when I was first licensed (1962) 2M AM was the only phone a Novice could do. With the help of my uncle I constructed a 2M AM transmitter from an article in the Handbook and had a ball with it.

Presently I'm just running FM & packet on 2M, but I have plans to build a plate-modulated AM amp for 2M using my FM rig as the oscillator/multiplier chain (and tapping the audio circuitry to drive the modulator). Not sure if I'll do it solid state or tube, though I'm tending toward using a 4X150 or a 4CX250 (my Kenwood TM-D710 should be able to drive either tube just fine).
How is APRS used by most Hams? sdowler59 on 19/9/11
Steve, the uses for APRS are only limited by your imagination. In this area (NE Ohio) APRS has proved very useful in public service events, both to keep track of where people are but also in sending messages. I'll bet similar uses are common in California as well.

Personally, in addition to what I mentioned above I use it for keeping track of ham friends (whether they are on the air and what repeater they are monitoring - the Kenwood rigs that do APRS have a provision to automatically include your voice operating frequency as part of the beacon packet. Not sure if the Yaesu VX-8 series will do that or not). Remember too that since the radio has a built-in TNC it can be used for other modes (like SSTV & packet) not just for APRS.

One of the guys in our local club has a VX-8DR and loves it, though he's a bit unhappy about how quickly the battery runs down. I'll bet a lot of that has to do with all the additional circuitry for the dual receive & the digital stuff. Before you decide take a serious look at the Kenwood TH-D72A as well.

Back to Top