Lscott
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Posts posted by Lscott
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1 minute ago, marcspaz said:
That image has a great looking setup! Ill check out the ZIP when I get home.
The antenna is screwed into a really short UHF barrel adapter and the other end has a length of RG-8 coax coiled up then reduced to a short run of RG-58. The whole thing is attached to a sawed off clothing display rack I found in the trash. A stainless steel hose clamp is used to hold it on the end of the tube along with 4 brass rods, about 1/16 inch diameter and approximately 19 inches long, bent down at roughly a 45 degree angle for a ground plane.
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42 minutes ago, marcspaz said:
Honestly, I don't know if it's just my antennas, but I have a CA-2x4SR both in NMO and UHF style and they both kinda suck. The SWR is fine everywhere except on 462 MHz frequencies. But they just don't seem to perform well compared to some of my other antennas. Like, to the point that I don't use either of the anymore.
At one point, they were my favorite, for reference.
I discovered the antenna is sensitive to the mounting location and type of mount. I've attached a zip file of some other tests I did with different mounting locations and types of mounts, like magnet - ground radials etc.
This was one of the better mounts and location in a home office setting inside a room.
https://forums.mygmrs.com/gallery/image/268-ca-2x4sr/
- Sshannon, marcspaz and wayoverthere
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11 minutes ago, WRWM519 said:
It is dual band, 2 meter and 70 cm, listed as:
Dual band MURS / GMRS Slim Jim Antenna with 10' or 16' Cable.
In the description:
Dual band versions Feature Trapped UHF section for proper band alignment.
I cannot say "what it is tuned for" aside from its being listed as GMRS and having the 2m/70cm tuning.
Thanks for the question.
I've done an SWR scan of the dual band, MURS and GMRS, version I have. The testing was done with the antenna hanging by a non-conductive cord. These antennas are not that broad-banded.
https://forums.mygmrs.com/gallery/image/284-n9tax-murs-gmrs-scansjpg/
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17 hours ago, wrci350 said:
It's advertised as "140-160/435-465 MHz" but I just went out to my truck and swept mine and the SWR is about 1.75:1 on the 467 MHz repeater inputs, which is certainly acceptable. It's a gain antenna, but it's kind of ugly and 40" high, which pretty much rules out drive-thrus for sure!
I recommended one of these to a work buddy for GMRS. He mounted it on the driver's side fender of a pickup truck near the roof pillar. The match was reasonably good on the UHF GMRS frequencies. I've attached the scans I did with it mounted on his truck.
Being a 5/8 wave antenna it needs a GOOD ground plane to give acceptable SWR across it's operational range.
Antenna Scan Results (CA-2x4SR VHF TRUNK LIP MOUNT).pdf Antenna Scan Results (CA-2x4SR UHF TRUNK LIP MOUNT).pdf
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1 hour ago, marcspaz said:
Over the past few years, I have tried just about every commonly discussed antenna available in the US. I literally have 8 or 10 antennas sitting in my office and garage right now, and 4 more in/on the truck.
Anecdotal I know, but the absolute best antenna I have used for 2m/70cm/GMRS is the Diamond NR-7900a. It's rated for 300w/250w and, 3.7/6.4 gain. Real-world, it far out-performs my dedicated MXTA26 GMRS antenna, which is the best dedicated GMRS antenna I have used. Not only is the range the best and able to handle the most power, the SWR on 146.52 is 1:1, on 446 it's 1.3:1, on 462 it's 1.6:1, and on 467 it's 1.5:1.
The Diamond NR-770 is a close second. The power ratings are a little lower at 200w/200w, the gain is a little lower at 3.0/5.5, and the SWR is the same everywhere but 462, where it's a little higher... 2:1. It's 1.4:1 on 146, 1.1:1 on 446, and 1.5:1 on 467 (which is where I spend most of my time). The slight sacrifice in performance benefits does yield a smaller, thinner, lighter antenna that is more discrete. However, I still prefer to use the NR-7900.
I tested a Diamond CSB7900 and the match wasn't that good.
A Diamond SG7500A tested OK on the Ham bands but not good for MURS or GMRS. Maybe with some tweaking It might work.
https://forums.mygmrs.com/gallery/image/283-sg7500a-swr-scans-2jpg/
The only antenna I have that works great on Ham, MURS and GMRS is my old trusty Comet CA-2x4MB. Unfortunately they don't make them any more. I have two, one is new in the original packaging. The other one the fold over spring is shot so I have the antenna is permanently fixed in the upright position. Otherwise it still works fine, but it's a huge monster, about 5 feet tall.
https://forums.mygmrs.com/gallery/image/282-ca-2x4mb-scansjpg/
https://forums.mygmrs.com/gallery/image/259-ca-2x4mb-jeepjpg/
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6 hours ago, gortex2 said:
Unless its an entire swap out most systems will migrate and allow phase 1 for a certain time to get folks into new stuff. Because of that you see less at good prices. You can get Type II dirt cheap now. Still if you search you can get XTL in both VHF and UHF for a couple hundred dollars with some searching. The issue is knowing the exact flashcode you need and band.
Most of my stuff is Kenwood. As far as I know only the new NX-5000 series supports P25 Phase 2. All their older radios are Phase 1, including the few I have. No upgrade to Phase 2 that I know of. If somebody wants Phase 2 they have to dump their their old radios. The feature license key to enable P25 on the new radios is almost $600! It doesn’t matter if it’s an HT or mobile, same price. For DMR or NXDN conventional it’s about $40. Yeah, dirt cheap. Trunking is another feature key add-on. The price list attached is for the HT.
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14 minutes ago, Sshannon said:
That’s true, but while a grandfathered license limits them to a specific frequency it doesn’t grant them exclusive use of the frequency now. I don’t know if it did in the 90’s when the incident occurred.
Unfortunately the typical user thinks that a licensed frequency grants them exclusive use of a frequency. That might be how it was explained to them when they got the radios. Some will be receptive to an explanation. Others, unfortunately, will tell you to go bugger off and quit using "their" frequency/channel. Their learning experience will be longer and more stressful.
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5 minutes ago, WRWE744 said:
The better question being, How do you even pronounce that?
Kay-Gee-Dash-Nine-Three-Five-Gee.
- Sshannon and kmcdonaugh
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1 hour ago, jeffsimmons1960 said:
That could be. I didn't push it, I didn't know well enough to give them an argument. I thought I was on a half watt FRS channel.
Since you can't recall it's just speculation they might have been licensed to use that frequency at the time.
I remember having an on-air disagreement with a person using a radio at the now de-funked Troys-R-Us store a mile or so from my old apartment on the MURS service. They said it was a licensed "Private" 900MHz frequency and I had to get off the air. Dah!! 900MHz? They were smoking something. I informed them it wasn't 900MHz, it's a VHF frequency now a part of the MURS service and is shared between users, then bluntly told them I wasn't leaving the frequency. I wasn't interfering with their communications, they apparently didn't like the idea they had to share it.
I'm sure there are many other cases where old business users still think they have exclusive use of a particular frequency. For example the local mall by me is still routinely operating under GMRS, they have a repeater in operation (462.575/467.575), but their license expired years ago. They continue to operate unlicensed to this day. Since it expired they can't get it renewed for business use. See attached files from the FCC database.
Before anyone gets tied up in a knot I would recommend researching the business/frequency first to see if they are in fact licensed. There could be a few legitimately grandfathered licensed users out there.
Lakeside Mall KAB1523 GMRS - Admin.pdf Lakeside Mall KAB1523 GMRS - Main.pdf
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18 minutes ago, BoxCar said:
You're in for it now. Constant questions, debate and the pursuit of ever newer and better radios!
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54 minutes ago, gortex2 said:
Correct Phase 2 currently only works in trunking scenarios. Again the APX is like the XTL not all are sold with TDMA. WE have multiple SAR APX radios with FDMA only in the flash code. Our newest radios were ordered with TDMA but we are still not using it.
I'm hoping as more systems switch over to Phase 2 for trunking the older Phase 1 radios will show up on the used market for reasonable prices. The Phase 1 radios are great for Ham use, simplex and conventional repeater operations. So far the Phase 1 radios I'm interested in are still selling used for a premium. The NXDN and DMR radios are generally selling for lower prices.
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8 hours ago, jeffsimmons1960 said:
Hello, new guy here, first post. Back in the 90s, I was at a local fairground using an FRS channel talking to my son. Turned out the state constables or the fairground operators or somebody was using that channel for their operations, with obviously higher powered radios, and kicked me off of the channel. I didn't argue and went to another channel, but I've always wondered about the legality of that.
Back at that time the rules were different. It was possible for businesses to get a license for a frequency.
Second the FCC F'd up and allowed the sale of combination FRS/GMRS radios too. The manufactures did put a very helpful note in the box warning users that some of the channels, those above 14, were for licensed GMRS use only. Almost universal nobody read that, or if they did, just ignored it.
You might have found yourself operating on a frequency you weren't licensed to use in which case being told to leave wouldn't have been unexpected.
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54 minutes ago, WRWM519 said:
but am told that I have weak reception of my signal.
The answer hinges on exactly what you mean by the above. It could be anything from low audio volume to a lot of white noise/static on your signal. The remedy depends on the symptom.
Since you are zeroing in on procuring a mobile radio to shuttle between the vehicle and house you can try that and see what improvement if any you get.
With 25 feet of RG-8X coax you're losing about 3.65 db, 57% of your transmitter power at 467MHz, based on a chart I have for coax cable types in just the cable run.
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3 hours ago, WRVU874 said:
I Bought a few used TK880s, I could use a little help:
1. Does anyone know why C152, the 1000uF would be removed?
2. The I/O (Power switch) has been set up to turn on and off the audio amplifier (I believe this is a power saving move for use a porta-peater). Any information on returning the I/O switch function to power On/Off would be appreciated.
Frank
I suspect C152 was removed because it failed at some point, likely shorted, blowing the in-line power fuse. Running off a regulated supply it might not matter so whoever did it just didn't bother to replace it.
Just a guess here. I haven't screwed around with the programming software but the power switch thing might be a programmable option to keep the radio on whenever the vehicle is running, turns off when the vehicle is off thus nothing for the operator to forget, like turning off the radio thus draining the battery.
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1 hour ago, WRKC935 said:
a radio that is Phase 2 compliant like the APX will still operate 'Phase 1'.
Unless I'm mistaken I don't know of any Ham repeater systems that use trunking and I believe Phase 2 is only for trunking systems so it's not an advantage on Ham bands. I'm not sure but I thought I read, a long while back, where it was discussed extending the P25 TDMA to conventional operation too.
I asked about the encryption since my NX-200, NX-300 and the TK-5220, TK-5320 has an optional AES/DES module available for them, which is expensive. The NX-1300DUK is only available with ARC4 as a feature license upgrade, no AES or DES. I haven't had the luck of getting a used radio with one of the modules in it yet. If any had one the owner took it out before selling the radio. I'm sort of surprised the Motorola radios seems to show up with the feature from time to time.
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24 minutes ago, gortex2 said:
I know of a couple P25 repeaters in the DC area on amateur radio. One is P25NX not sure on the others. I'm normally on simplex when i zing thru that area.
The other thing I noticed is the radio uses the older IMBE codec, which I think was the standard at the time for P25. I think the newer AMBE+2 is compatible with it. I have a few TK-5220's and TK-5320's that use the newer codec. Have you experienced any issues with communicating between radios using the two?
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I see the radios are analog/P25. Is there any significant P25 activity around your area? The radios also have various encryption modes. Are any of those active in the two you have?
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You can save yourself some trouble by testing indoors if you have a magnet mount. Stick it on a good ground plane away from things by several feet. I keep a sheet of duct work sheet metal in the basement for testing small VHF and UHF antennas.
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17 hours ago, WRWT868 said:
Yep, had it bounce on the floor, roll under the couch. Anyone know what size and pitch it is, I'll just get a couple and keep one in the door and another in the cable otherwise that screw isn't going to last 24 hours... What a hooky set up..
If you can't find it take the radio to a local home improvement, try Home Depot or Lowes. They have a good selection of fastener hardware, many in metric. If it looks like it might fit try one out in the radio to see if it screws in without jamming. If it does and it's a bit too long you can sand/grind off the excess length.
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2 hours ago, WRQC527 said:
I've also found that dropped screws defy the laws of physics. If you drop one from three feet, it bounces 18 feet. And when you're looking for it, you won't find it, but you'll find the one you dropped last year.
Tiny screws you drop on the floor almost always seem to roll under the table, chair or cabinet where you can't reach it. And if the part is plastic you typically step on it first, then it breaks and that's when you find it, under your foot.
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3 hours ago, WRWE744 said:
What is the best way to ground a base station antenna so my equipment or house isn't fried by lightening?
Here is some material to look over.
Lightning Protection Grounding Solutions for Communication Sites.pdf Grounding Tips for the Shack.pdf
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3 hours ago, WRWE744 said:
Can I set up a repeater using two radios and a control box, or do I need a duplexer?
Short answer most likely yes, with a duplexer. For more info on repeater building go to the link below.
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3 hours ago, JoCoBrian said:
If I don't like the way a product is licensed, I don't buy it, but I don't steal it. Intellectual property theft is a real problem.
I paid $400 for the radio. I seriously doubt Kenwood hasn’t included software development cost in that.
They also charge for feature licensing too. That I understand. I specifically paid to have the DMR function enabled when I purchased the radio. The price was reasonable.
I’m also considering getting the ARC4 encryption feature too. That involves screwing around with Kenwood’s license management software, which just so happens to ALSO requires a license key to enable!!! It uses the same Internet based licensed server BS the radio programming software requires. Gee? Really? Fortunately the license keys are free, and are targeted for dealer’s use. Kenwood doesn’t want users to be upgrading their radios either. I had a Ham radio friendly dealer send me a license manager key good for 10 installs. He also will sell the feature license keys to the radio user too. I got a quote on what those would cost.
Questions about wattage versus antenna in my situation
in General Discussion
Posted
The antennas are hand built. You might have got one that was better constructed. Also the connectors on the end can influence the results too. I have two of these antennas, both dual band. One is cut for MURS/GMRS and the other is for 2M/70cm. I forget which connector is on which antenna. One had a PL-259 plug while the other one had an "N" connector.
I might take some time to re-scan the MURS/GMRS version.
I've attached the scans I did for the 2M/70cm version.
I found some scans, the photos are poor quality, the builder posted on his web site. They are for the Ham bands. The best I can see it the UHF scan shows an SWR of 1.82(?) at 439MHz and 1.34(?) at 450MHz.
N9TAX-2M-70CM-VHF Scan.pdf N9TAX-2M-70CM-UHF Scan.pdf