[digitalradio] Re: 70cm -2M-6M-10M fan dipole ?
Andy, Will you be cutting the 2m/70cm portions for FM or the SSB portion? Those two might get tricky as 70cm is a harmonic of 2m. It of course can potentially be advantageous if using one antenna (or radiator) for both so long as you can live with the way it radiates. Radiation lobes for 2m will not generally be pointing the same direction as 70cm. People quite often build vertical J-poles as a dual band antenna, and while the vast majority load just fine on both it is absolutely not true that they radiate efficiently on both. On 70cm they radiate both up 45 deg down 45 deg- leaving the horizon virtually uncovered. Which is not to say one can't use it for a given repeater on 70cm but it won't be efficient no matter how you slice it. (Fong J-pole is an exception to this rule since it has a phasing section which corrects this- if you want a truly omnidirectional this is an easy inexpensive way to get those two bands in a vertical) A fan dipole built as a sloper this may or may not work for you and is likely to be somewhat if only slightly directional, but 70cm might be iffy. Horizontal likely should be no problem at all (though more directional again), so long as it worked out resonant for both bands. It is all in making the radiation go somewhere useful. I have not calculated nor experimented with this on the SSB portions yet; though a rough guesstimate suggests they should line up close enough. Simply leaving separate wires for each 2m 70cm will likely leave the 70cm section doing little unless you install traps on the 2m wires- assuming the 2m portion remains close to being resonant on both 2m 70cm. At least this is my recollection from an experiment some years ago- I recall I could never get the 70cm element to do much no matter how I oriented it. Wire is cheap, so have fun playing with it! By the way, you'll find the interactivity (the multiple wires trying to detune each other) reduced quite a bit if you can manage to keep the wires far enough apart. Spreading them out in different directions to some degree can help a lot- if that is an option at your QTH. These are all quite short which should help. Stu AF6IT --- In digitalradio@yahoogroups.com, obrienaj k3uka...@... wrote: I am planning another HF installation soon and may have a 33ft mast begging for some extra creative thing to hang off it . I do not do 70cm -2M-6M much and think I should , just to be able to get out when there are bands openings. Nothing with DX in mind, just something omni-directional would do (or ANY direction) I was thinking about a fan-type dipole , one feed line going to dipoles for 70cm - 2M - 6M and maybe 10M. Most likely not fully horizontal , more of a sloper. Any thoughts on something like this? Quite a wide range of frequencies. Andy K3UK
[digitalradio] Re: ROS Developer will continue to auto-spot despite complaints
Why is it we're still even discussing this? The mode is questionable, the quirks are many, the value is dubious, the author a non-ham with a BIG attitude, and he controls our computers. (Not mine, glad I never got around to downloading) Why should we be his pawns and feed his ego? Best thing we could do is simple end the debate, change the subject, and allow ROS to die its deserved death by neglect. It didn't have to go that way, but it is what it became by choice of the one who engineered it. Laurie several others critiques seem quite valid. So why the ongoing debate? Let it end here now! Just my cent worth. Stu AF6IT --now SK on the subject --- In digitalradio@yahoogroups.com, Laurie, VK3AMA group...@... wrote: With this action (or inaction) from Mr ROS and considering all of his past actions/comments it becomes clear (to me) that he has an agenda and Hams are being used as beta-testers to help fulfil his ultimate goal. He has shown several times an unwillingness to embrace Ham Spirit and Ham Operating Standards. His Agenda? I suspect it is commercial in nature. My thoughts. de Laurie, VK3AMA
[digitalradio] Re: 3rd Generation Digital radio
A perhaps narrow outsider's opinion: There is potential here for both good and for wreaking havoc with fellow users of VHF/UHF amateur bands given a paradigm shift into a G3 digital era. Improving upon packet's abilities could be a very good thing- particularly for those involved in EmComm. But running analog FM users away just because commercial gov't users have had the change to digital crammed down their throat would be a very bad idea. If it can peacefully co-exist with current users- then no problem! As a potential user I confess that I'm not terribly interested in digital modes up here. Adding more specialized equipment has no appeal nor any advantage to my operating style. HF digital is much more exciting useful to me. (YMMV) My greatest fear is that someone in an urban upper 5% utilization zone might find a listening ear in the FCC who would recklessly force a draconian change to make us all go 100% digital VHF above- even for the 95% who have no trouble finding available analog freq's. This is ham radio after all- not hard core government EmComm! (Which is I suppose STILL waiting to see how beneficial the move will prove to be for them) One other comment: Tactical ham frequencies??!!! What in the world??? For ham SWAT teams? LOL Didn't Indianapolis PD get into trouble for less than that? :-) 73 de Stu AF6IT --- In digitalradio@yahoogroups.com, Greg n9...@... wrote: If the first generation of digital was PACKET-IRLQ-Echolink-APRS (generation Zero was CW and RTTY), then the second generation was D-Star. D-Star brought everything together along with digital voice. While D-Star is great, its technology is already dated. So what will the third generation of digital radio look like? I am thinking that it will be more like the Trunked Radio (digital) or either P25 phase II or TETRA. TETRA is 25 Khz wide channel with four TDMA slots with a very low cost handheld (under $400) and is used in Europe within the 400 Mhz band. P25 digital currently is 800 Mhz, FDMA (25 Khz channel). Phase II will move to a single 12.5 Khz channel with two TDMA slots. Additional capacity can be added with additional repeaters (12.5 Khz) working under a common controller. So, could we do something like that within amateur radio? We have to be above 220 Mhz in order to get 9600 baud rates. If we look at bands, 900 Mhz may be to high and 440 may be too crowded. It was suggested that we go 220 as it gives a mix of characteristics of both 2m and 440 and is fairly open. If we go to P25 (phase II) we do have to overcome the cost of the VOCORDER. That could be done with open P25 in software in an software defined radio (SDR). Most of the military radios these days are SDR. A trunked system would allow us at least state wide communications that would include voice, data and position reporting (APRS). Also that one could link into the system via VoIP (like D-Star or Echolink). A small community might only need a single repeater with two FDMA slots. In big cities it might be that there are multiple repeater sites with two or three repeaters (4 to 6 slots). Also five simplex frequencies for tactical operations or remote areas (like using 146.52 and 144.39 now). Using 9600 baud rates would allow for greater amounts of information. And an SDR would be flexible enough to handle such data rates. Any comments or ideas? Let the flame wars begin.
[digitalradio] Re: Initial thoughts on SDR (eye tracker tuning)
So we would stand on our head to change from USB to LSB? Or just reverse the headphones? :-) (Sorry couldn't resist!) de Stu AF6IT --- In digitalradio@yahoogroups.com, Cortland Richmond k...@... wrote: I would suggest an intuitive interface; stereo headphones with tracking so turning one's head tunes the receiver, frequencies below the tuned point sent to the left earphone, frequencies above, to the right. Now just turn your head until something interesting is audible straight ahead, press a switch or click on an icon and Bob's your uncle! (sneaking in English) This could be pretty easy with some of the virtual reality gaming systems but we might not need the video outputs. Or maybe we would Imagine spotting the multiplier you need on the heads up display, turning your head until it's heard straight in front, and ZAPPING it with the mouse. Nerd Preferred! Cortland KA5S Cortland
[digitalradio] Re: Techs on HF digital
Gary, From the ARRL website: Novice and Technician classes: 28.000-28.300 MHz: CW, RTTY/Data--Maximum power 200 watts PEP 28.300-28.500 MHz: CW, Phone--Maximum power 200 watts PEP http://www.arrl.org/FandES/field/regulations/allocate.html#10 http://www.arrl.org/FandES/field/regulations/allocate.html#10 Personally, I do not particularly encourage Techs to use digital modes on 10m, and would strongly oppose opening any other Novice/Tech CW sub bands to digital mode use by Techs. Band plans are already in a state of chaos and this would probably render those novice areas nearly useless. It would be a free for all the way I see it. It is sufficiently complex that I see plenty of Generals Extras have a hard time using digital modes appropriately. Don't get me wrong, I love digital modes and welcome their responsible use- but if it cannot be done at least as orderly as now then we had best not open the gates to a herd of exuberant greenhorns without sufficient coaching. There are still three license classes for a reason! Now if you propose that local clubs or even via online that some classes be put together to coach Techs into upgrading to General with a focus on setting up using digital modes (or for that matter CW) I'd be all for that! The biggest obstacles keeping people from upgrading is the lack of readily available elmering and the persistent attitude of the crusty OF's who think they own HF. Has been that way for the 20 years I've been licensed at least. Stu AF6IT --- In digitalradio@yahoogroups.com, Gary grwes...@... wrote: I thought I'd run something up the flagpole and see if anyone salutes: snip So... Here is the idea. Would you be amenable to allowing Technician Class licensees to operate digital modes in the Technician CW bands and do you think that would be of interest to new hams? I would imagine, the license limitations would have to state something like a maximum of 300 baud and 500 Hz bandwidth with a 200 watt power limit. There may be other limitations that might be nice to toss into the mix but this is a starting point for discussion. Your thoughts? Gary - N0GW
[digitalradio] Re: Ham Radio Programs for Windows 7
Skip, yes Windows 7 has a compatibility mode- IF you have 7 Pro or higher, IF you have a compatible dual or quad core processor (not all enable the threading mode required), PLUS your motherboard's BIOS allows the enabled CPU's mode to make it go. A lot of ducks must be in a row... FWIW, this is the same setup for running virtual machines in your computer, though I'm still wondering why in the world one would want to in a non-server given the license requirements not changing. Running another virtual OS still requires a beefy machine, and the license and installation of that OS and requires more overhead than simply running that other OS more cleanly from another partition or hard drive. From a server- that is another matter entirely. Stu AF6IT
[digitalradio] Re: Which radio ?
The FT-450 is the superior HF rig of the two absolutely. No other current rig can better or equal it without nearly doubling the price! The IF DSP requires no extra filters works /remarkably/ well. It costs less, too. Can you live without 2m 70cm? Then the choice is made! Stu AF6IT --- In digitalradio@yahoogroups.com, Ted Wager t...@... wrote: I am returning to amateur radio after 15 years qrt and looking for a new radio Main interests are listening hf and digi modes, principally psk..My choice is down to either the yaesu ft450 or the Yaesu ft-857d.Any comments on my choice welcome and should I look at any other radios ? -- Regards Ted Wager High Peak UK Using linxmint Helena
