-
Posts
3230 -
Joined
-
Last visited
-
Days Won
101
Content Type
Profiles
Forums
Events
Gallery
Classifieds
Everything posted by Lscott
-
How many people really use the VHF radio MURS service?
Lscott replied to Lscott's topic in Multi-Use Radio Service (MURS)
I know the FCC doesn't like the idea of mixing services together in one radio so this idea likely will never happen but from an operational point it makes sense. Most Ham HT's are dual band so a FRS/MURS specific dual band license free radio is possible. Now that most FRS channels, NOT GMRS, are now limited to 2 watts, the same as MURS, combining both in the same radio would work out. Both are license free services. Nether service allows repeaters so no issue there. The radio would have the antenna permanently attached per FRS requirements however. There are plenty of cheap dual band radios with tweaked firmware to comply with FRS or MURS. Allowing both in one radio you get better utilization of the hardware. Dual band rubber duck antennas are common for Ham HT's and wouldn't be a problem to tweak those for FRS and MURS. Plus if FRS UHF is unsuitable outdoors the user would simply try one of the MURS VHF channels. No need to carry around two radios. -
GMRS Real World Emergency Communication Experience?
Lscott replied to Lscott's topic in General Discussion
The only problem with standards is there are so many of them. It seems one of the issues is there is no common protocol to use. I've read about several on this forum alone. There is even one used in the Ham world I haven't seen mentioned yet. A number of posts in other forums claim they didn't have much luck with this one either. ---------------------------------------------------------------------------------------- Amateur radio Wilderness Protocol The Wilderness Protocol recommends that those stations able to do so should monitor the primary (and secondary, if possible) frequency every three hours starting at 7 AM, local time, for 5 minutes starting at the top of every hour, or even continuously. The Wilderness Protocol is now included in both the ARRL ARES Field Resources Manual[2] and the ARES Emergency Resources Manual. Per the manual, the protocol is: The Wilderness protocol (see page 101, August 1995 QST) calls for hams in the wilderness to announce their presence on, and to monitor, the national calling frequencies for five minutes beginning at the top of the hour, every three hours from 7 AM to 7 PM while in the back country. A ham in a remote location may be able to relay emergency information through another wilderness ham who has better access to a repeater. National calling frequencies: 52.525, 146.52, 223.50, 446.00, 1294.50 MHz. Priority transmissions should begin with the LITZ (Long Interval Tone Zero or Long Time Zero) DTMF signal for at least 5 seconds. CQ like calls (to see who is out there) should not take place until after 4 minutes after the hour. ----------------------------------------------------------------------------------------- http://www.arrl.org/files/file/Public Service/ARES/ARESFieldResourcesManual_rev10-2019.pdf People buy a radio and some batteries then stick them in a drawer. The only time they get used is when either the roof comes off or they need a boat to leave the house. One point to consider is the person who knows how to use the radio in a group might be the one who desperately needs help and unable to use it. Reading through a few posts on other forums some suggested getting one or more of the personal locator beacons. https://www.sarsat.noaa.gov/emerbcns.html Anybody have any experience with these? I think these are simple enough even a kid should have little trouble activating one. -
Just about everything. Don’t bet against Murphy either.
-
How many people really use the VHF radio MURS service?
Lscott replied to Lscott's topic in Multi-Use Radio Service (MURS)
Yup, some people like to screw with the local Walmart on MURS. -
Lighting arresters do fail. How many people check to see if their arrester is any good? I didn't want to imply not to use an arrester, but disconnecting the coax is additional protection. While having the arrester tied to an earth ground is required no mention of the quality of that earth ground was mentioned. One could sink a 10 foot rod in the ground only to later discover the earth around the rod is mostly dry with a fairly high resistance between it and a ground rod sunk in a patch of soil with high conductivity. In fact some installations they even put salt crystals in the ground around the rod down a bit to improve the soil conductivity. A ground rod where the resistance is too high is basically useless. https://iaeimagazine.org/electrical-fundamentals/the-5-ft-ground-rod-and-its-little-known-use-in-the-nec/ https://electrical-inspector.blogspot.com/2013/05/verifying-ground-rod-installation.html https://handtoolsforfun.com/how-to-measure-ground-rod-resistance-with-a-multimeter/
-
I wouldn't recommend that. Lighting strikes are very high voltage and current. Chances are the RF switch would have the internals destroyed, melted contacts and so on, and the current will take whatever path to ground it can find, including jumping any gaps inside of the switch. Your best bet, provided you know a storm is coming, is disconnecting the coax from any equipment and keeping the ends away from anything conductive. A few people claim they put the ends in thick glass jars. Even near strikes can induce high voltages in the cable ruining to equipment, similar to an EMP event. A lighting arrestor won't guarantee no damage will occur but will go a long way in reducing any that does. One thing that people don't think about is build up of static electricity, even on bright sunny days. If there is no way to bleed it off the voltage that builds up can destroy RF front ends in radios. You may have seen it mentioned in the specifications but never really thought much about it, some antennas are built with a DC ground, due to the driven element(s) would otherwise be isolated, for exactly the above reason.
-
GMRS Real World Emergency Communication Experience?
Lscott replied to Lscott's topic in General Discussion
You have a point. However if that channel is used for normally everyday type of communications the SAR team would have to monitor the radio every time the squelch opened to see if it was emergency traffic. Of course if somebody forgot to program in the right code, or no code, they would be SOL. When an emergency strikes is NOT the time to figure out how to program your radio. -
Afterwards you could hang them up as practice targets at a pistol range just to be sure.
-
Oh, ok. I thought you had a bit of fun decommissioning old hard drives.
-
Ok. I think dropping the CW requirement helped get a few more people to get interested enough to take the test and get licensed. The hobby can use a lot more young people in it.
-
That battle was argued to death years ago and lost in favor of dropping the requirement. The reason why it was dropped, from what I read at the time, had to do with many of the Ham bands being shared with government stations which primarily used CW. The Hams were typically secondary users on the bands early on so when a government station need to use the frequency the Ham station had to better understand when told to get the "F" off. Now that almost, to maybe none, use CW exclusively there is little reason to know it. That's why it got dropped at the time by the world radio conference. It took the FCC time to catch up to other countries in dropping the requirement. The old timers cooked up all matter of reasons why it should be kept. Everything from "I had to so you have too", emergency communications, CW will die out, bands will be overflowing with CB'ers, just plain bragging rights and as a filter so some can feel superior to other Hams being a member of an exclusive club just to name a few. None of the negatives have panned out. In fact at every swap I go to there is always a healthy number of young and old Hams hanging out by the guy selling CW keys. It's popularity I don't think will ever die out. The only difference is people learn it because they want to, not because it's a requirement.
-
I've seen this with a number of high gain antennas on UHF, at least mobile ones I've tested. I attribute this to the different sections of the antenna with the associated phasing elements between them. If you're lucky the valley of the SWR ripple is where you want to operate on GMRS. Otherwise you could end up near the peak. It all depends on the particular antenna and sometimes it's mounting location sensitive, close to the ground or elevated some 10's of feet up on a mast. While some antennas are marketed as ground independent they still show some effect, an improvement, when a small ground plane is present. There are some people who added a small set of ground radials at the base, of the antenna, when mast mounted and claim it made a noticeable improvement in the match. The ground radials seem to help keep RF off the exterior of the coax shield which shows up as a higher SWR at the radio end. Some antennas like the J-Pole/SlimJim types have a ferrite installed on the coax at the feed point, or a loop of several turns of coax, which is necessary to keep RF off the coax shield. I've also seen mobile magnet mounts, like a CB antenna, where the SWR changes when the coax is moved around, not the antenna. The antenna doesn't couple into the metal very well through the base because it's too small for good low impedance capacitive path to ground so some of the RF ends up on the outside of the coax shield. I even had this problem with a 6M 1/4 wave magnet mount on a van.
-
I assume it's the same sort of stuff used on July 4'th.
-
The few hard drives I had fail I opened them up, removed the platters and then physically destroyed them by bending them up before depositing them in the local dumpster. No chance anybody was going to swap them into a functioning drive using a clean room. The company I work for any old computers they trash have the hard drives removed and separately destroyed, physically, as a normal security protocol. Also using the so-called multi pass random data write/erase programs aren't that good either. The area on either side of the read/write heads may contain enough residual field for the head to read in some cases. Reprogramming the drive's micro-controller to offset the head position over the track edges could still allow data to be recovered from the drive. You best bet is to destroy the platters.
-
A Ham buddy picked up a "ToughBook" laptop at a swap a few years ago that was used as a mobile data terminal in a police car. It still had the software installed on it and I think it even updated itself. The login to the server however didn't work. That would have been very interesting if it did.
-
When I lived in an apartment years ago I went trash picking around the complex. Surprising how many computers you find that were fully functional and still had stuff on the hard drives! Used parts from some to upgrade others, mostly memory, and sometimes got a new cheap hard drive. Lot of PIII’s, Celerons and a few P4’s. Speed from a few hundred MHz up to a GHz. I loaded various versions of Linux, mostly Fedora at the time, to run on them. I stuck them on my network and let them run 24/7 until they died. Then just built new ones out of the old ones I find.
-
Also congratulations on passing your extra exam. When the Morse code requirement was dropped I went for the General and the Extra at the same test session and passed. I did get dirty looks from one of the VE's, must have been in his 80's, as I walked out. Oh well.
-
TK-880 programming: Operator Selected Tone
Lscott replied to fremont's question in Technical Discussion
You sure the "B" key even works? You might have a bad keypad. Try assigning a different function to the "B" key and see if that works. Also what settings do you have under "Optional Features 1" and "Optional Features 2"? I don't have this radio myself but I do have the software installed on my computer. I was helping somebody else out a long while back. -
GMRS talking to FRS...and other GMRS--Ch 15-22 bandwidth selection
Lscott replied to fremont's question in Technical Discussion
Looks like you have the non MPT model. MTP is a trunking format. The specifications you linked to mentions zones so you might be in luck after all. -
GMRS talking to FRS...and other GMRS--Ch 15-22 bandwidth selection
Lscott replied to fremont's question in Technical Discussion
I think he’s stuck with the 8180. I just looked for the specifications. https://pdfs.kenwoodproducts.com/28/TK-7180&8180MPTBrochure.pdf -
GMRS talking to FRS...and other GMRS--Ch 15-22 bandwidth selection
Lscott replied to fremont's question in Technical Discussion
This is why with my Kenwood commercial radios I have two zones, banks, one where all the channels are wide band for GMRS and the other for narrow band for FRS. That was the simple solution for me. If you can’t do this with the popular 805’s, 905’s or 935’s and various GMRS specific mobiles maybe it’s time to look at a good clean commercial radio from Motorola, Kenwood, Icom etc. that has the ability to do it. The radio I frequently carry around for Ham and GMRS/FRS is the TK-3170. I have 6 to 7 zones of channels programmed in it depending on what service I’m operating under and bandwidth. https://pdfs.kenwoodproducts.com/9/TK-2170&3170Brochure.pdf -
This is a point that doesn’t get addressed much if at all when recommending a radio. Seems most people focus on the number of memories, can it do spilt tones, does it have repeater access etc. If commonly used features can’t be accessed or changed through the radio’s keypad that might result in the radio being in a practical sense useless. For example I have some very good 16 channel Kenwood LMR radios, but there is noway to change squelch level except through the programming software. I had to pick a level that works for most cases and live with the fact in a low noise environment there will be stations I can’t hear.
-
Yeah, they might change their mind and leave it $70 since people are paying it and make it official.
-
That sucks. Some of my favorite Kenwood LMR HT’s I can assign the function OST, operator selectable tone, to it. The programming software allows me to enter about 38 to 40 tones in a table that you can select from using the OST function.
-
The high gain antenna would be nice BUT the match sucks. That’s leaves the lower gain one. Since this is for a dedicated application, repeater, I wouldn’t worry about the SWR on the 467.xxx frequencies since these are all inputs, you’re not TX’ing on them. The lower SWR on the 462.xxx frequencies is what you need to be watching since those are the repeater outputs.