Lscott
-
Posts
2913 -
Joined
-
Last visited
-
Days Won
99
Content Type
Profiles
Forums
Events
Gallery
Classifieds
Posts posted by Lscott
-
-
3 hours ago, WRCQ487 said:
Nickel Machined Brass Construction
I've read comments where experienced radio tech's strongly recommend to stay away from Nickel or Chrome plated connectors and use only Silver plated type. The claim made is a film will form on the surface which has some rectification properties like a diode. The partly rectified RF is rich in harmonics causing all sorts of issues on RX and TX. I've also read about harmonic problems being traced to plain old rust on antenna towers for the same reason.
The last bit was used to advantage during WWII for the Foxhole Radios. The blue coating on the razor blade is really a type of iron oxide coating.
-
8 hours ago, WRWM850 said:
I just bought my first real gmrs radios; a few old beat up Motorola CP200's (upgrade from Baofeng starter)
does anyone know were to get the software and what the difficulty is on programing these?
Lesson number one. Research the radio before you spend your money!!! That means does it have the features you want? Do you just want the radio for GMRS or does it need to cover the Ham UHF band too? Can you buy replacement battery packs for it, are chargers available, can you get the programming software and cables? If it breaks can you get it repaired and at what expense? Are accessories like antennas, belt clips, external speaker microphones available? And finally can you get copies of the documentation for the radio like user manuals and service manuals?
For some people they want a radio that is FCC certified to operate on GMRS. Not all radios that can be programmed for GMRS have that. That requires checking the FCC ID on the radio in the FCC's database to check which "Parts" it has been certified to operate under. Some have the required Part 95 certification, most have at least Part 90 which is only good for the commercial frequency band. However many people use Part 90 radios, and so far the FCC doesn't seem to bother them, but it's not a guarantee.
For example I'm mainly a Kenwood radio guy, nothing wrong with Motorola I have a few XPR6550's, and some cheap Chinese radios, but Kenwood is what I prefer.
https://forums.mygmrs.com/gallery/image/261-e451d5e2-f358-40dd-95a1-af106f7e8584jpeg/
Kenwood has a new series of commercial radios out, NX-1000's, NX-3000's and NX-5000's. All very nice radios. The kicker is the programming software. It requires an Internet connection to their license server, the software is locked to one PC at a time, unless you deactivate it and transfer the license. Then there is the hassle of getting the software. Kenwood is targeting the programming and support to their dealer network. Trying to find a dealer that will sell you the software and license, which is $155 a pop, isn't easy unless you "know somebody" and there are a few out there. Due to the software licensing issue I had ZERO interest in looking at new or used models of the above. That is until somebody cracked the software for the NX-1000 series. Now I have one because I can get the software and installed it on several computers I use without the licensing crap to deal with.
https://forums.mygmrs.com/gallery/image/290-nx-1300duk5/
-
7 hours ago, dwmitchell61 said:
On channel 1 I am receiving a constant beep. I thought I heard some family chat in the distant background.
One of the neighborhood kids must have set his radio down with an emergency beacon or something turned on.
No channel 1 until the battery runs down, I guess.
Wait until they setup shop on your favorite repeater's output frequency and the kids are only a few houses away.
-
45 minutes ago, Wrvq441 said:
I recently tried something similar. My hand held can receive from the repeater just fine, but I am just far enough away from the repeater that I cant transmit to it.
So I had the brilliant brainstorm that I could set my personal repeater to receive from my hand held and transmit to the repeater that I want to use. My hand held would be set to transmit to my personal repeater and to receive from the repeater that I want to use.
My repeater software wouldn’t allow that kind of frequency spread, and it probably wasn’t legal anyway.
I too was spoiled back in the day with EMS where our Pack-Rat hand held would be repeated through our squad radio.
That's half duplex operation. Using two separate radios it's possible. For GMRS the mobile "receiver" radio would be set to one of the simplex channels. The audio output would be connected to the higher power mobile radio set to transmit on the remote repeater's input frequency. As you mentioned the output of the remote repeater would be received directly by the handheld radio. The handheld radio must have ability to be programmed for arbitrary split frequency operation. May of the GMRS specific radios have the frequency split "built in" and only setup for the main repeater channels, which won't work in this case.
You would still need a cavity duplex type filter the same as any other repeater. There are low power ones that would likely work and are tuned by the supplier at purchase. One would end up paying around $100 to $150 depending on model.
https://www.409shop.com/409shop_auctionsearch1.php?userid=100556
Also some type of "controller" would be required to couple the audio from one radio to the other and key it up. One of the Surecom models would likely work.
https://www.409shop.com/409shop_shopcat.php?&usercat=4934&parentid=4934
The advantage to the half duplex idea, if the owner is the only one using it, no ID is required. Every time the handheld radio user ID's the mobile transmitter ID's too. This would NOT be true if it was a full duplex system communicating with a remote repeater. The last point is one of the major issues with full duplex mobile repeaters. It's also a sticking point for Hams using full duplex cross band repeat mode on their mobile radio, which typically don't have a self ID function. Many do it, but it's not strictly legal.
-
For those that want a PDF version see attached file.
- Sshannon, axorlov and Charliewreq466
-
2
-
1
-
4 hours ago, WRUU850 said:
It is my understanding the site was lost.
Is that repeater going to be moved to another site?
-
On 3/23/2023 at 12:05 PM, axorlov said:
+246, +542, +653, -523, -647, -726 all are the same code. But it's unlikely Motorola will have any of them. More info here: https://web.archive.org/web/20220331074737/https://www.onfreq.com/syntorx/dcs.html
Thanks for the link. It was a long but very detailed explanation of DCS codes. I’ll have to print it to a PDF file and save it in my electronic document library.
-
3 hours ago, Radioguy7268 said:
I'd expect a comparable DMR NX-1300UK to come in around $400 +/-
That's about what I just paid for a NX-1300AUK5 with the DMR feature license added to it. It's now effectively an NX-1300DUK5. All the vendor had in stock were the analog only versions so I got the DMR upgrade feature license, which was fairly cheap. I don't need the NXDN feature license since I have a good collection of NX-200's and NX-300's already.
https://forums.mygmrs.com/gallery/image/290-nx-1300duk5/
I'm thinking about spending the $40 more or less to get the ARC4 enhanced encryption feature license, only good for DMR. That would make the radio so it's comparable with Motorola radios using the basic encryption also on DMR.
The basic model might be more along the lines of what they need. It seems that's the most popular model since it's cheaper.
-
2 hours ago, WRQI583 said:
Usually when they link repeaters together they use a UHF frequency to link two or more VHF repeaters together.
IMHO I think that has more to do with more spectrum is available on UHF. Using VHF for a link would use up more of the limited VHF spectrum for repeaters.
-
The new Kenwood NX-1300’s would likely be of interest to your company.
-
-
You also see small ones at the top of some communications towers. They are angled at about 45 degrees. The antenna is at the base of the tower pointing up at the reflector. Some people call these “periscope antennas”.
-
More info on passive repeaters.
- wayoverthere and WRUU653
-
2
-
A different MPPT controller brand might be better RF noise wise. The one I linked to the manufacture claims it doesn't generate the RF hash others do.
-
8 hours ago, bd348 said:
Given the positions shown here, was the UHF signal perhaps going along the valley north-east from the blue dot, bouncing off a mountain, then going down the other valley south to the green dot?
That's possible. There are such things as passive repeaters, nothing more than a huge sheet of metal acting as a reflector. The mountains could be doing that.
What might be more likely is some diffraction effects. Light waves, and RF waves, will experience diffraction when passing a sharp edge. In your case it could be the ridge at the top of the mountain. Enough energy diffracted downward to make communication possible.
Warning only math geeks should try to read this.
https://apps.dtic.mil/sti/pdfs/AD0117276.pdf
This isn't as bad and the illustrations make the explanations easier to understand.
https://www.ihe.kit.edu/img/studium/Wave_Propagation.pdf
-
12 minutes ago, tweiss3 said:
I have the KMC72 which sounds amazing, and is nice and loud for noisy environments, but it has the Kenwood data port connection.
I think that's the replacement for the old -42WD type.
-
8 minutes ago, HK2GO said:
I haven't purchased one yet but am leaning heavily towards the Kenwood KMC-45D. A bit spendy for what it is but something tells me I won't find a better one when it comes to sound quality, and it should last for a very long time.
A similar speaker mic is the KMC-17. I have a couple of those and my buddy says it sounds good on the air. It might also be cheaper than the -45.
-
19 hours ago, Over2U said:
What is the theory of a ‘no ground plane’ (required) antenna for transmitting on GMRS frequencies (i.e. ‘how does it work’)? Also, does such an antenna require a special type of cable?
Well it's the difference between a 1/4 wave long antenna verses a 1/2 wave long antenna. The minimum length antenna to radiate RF is a 1/2 wave length long by theory. Since a 1/4 wave length antenna is "missing" the other part, the absent 1/4 wave length, it has to be made up for some how. That's where the ground plane comes in, it doubles the antenna length so it looks like it's a 1/2 wave length long to the transmitter.
To make the idea simple to understand place your finger against a mirror so it's perpendicular to it. You'll see immediately the reflection of your finger touching the end of your real one. That's basically what the ground plane does for a 1/4 antenna, it "mirrors" the other half of the antenna so it looks like it's really a 1/2 wave length long.
With a 1/2 wave length antenna you have a choice where to attach the coax cable, in the middle or at one of the two ends.
If the coax is attached in the middle the impedance is around 70 to 75 ohms more or less. That's a reasonably good match to a 50 ohm coax resulting in an SWR of about 1.5:1, which all most all radios will have no issues with it.
For a vertical antenna the most convenient place is on the end. For some complicated reasons the impedance is far higher than the 50 ohm coax cable. For those antennas a matching section in built into the base. An example is the common "J-Pole" antenna. It's really a 1/2 wave length antenna with a 1/4 wave parallel transmission line matching section on the end. The feed point is selected such that the ratio between the voltage and current is 50, which is the required value for the 50 ohm coax. If the coax feed point was exactly on the shorted end the voltage would be zero, resistance = voltage/current, so the impedance would be zero. At the other end the current is nearly zero, the un-terminated end of the one element, thus the impedance is extremely high. Thus the match point must lie someplace between those two points.
This is about as simple of an explanation without getting deeper into the theory.
-
Have you considered swapping out the simple PWM charge controller for a MPPT type? In theory it should allow you to capture more energy and store it in the battery. With large changes in solar radiance and panel temperatures this will make a noticeable improvement IMHO.
These controllers seem to work rather well. For about 100 watts of panel power a 10 amp controller would be right for your application.
https://sunforgellc.com/product/gv-10/
-
1 hour ago, Sshannon said:
This is likely the same radio but with different firmware.
https://www.miklor.com/COM/Review_GMRS-50V2.php
https://www.miklor.com/COM/Review_50X2.php
The problem with most of the cheaper Chinese radios is the receiver section. They get de-sensed easy in strong RF environments and the selectivity can be poor.
Most radio users after a while will understand the receiver is what really counts. Given a choice between more power or a bullet proof receiver I would go with the better receiver.
-
7 hours ago, WRVG593 said:
Beware sad hams, this is a theoretical post and for "speculation".
So I'm looking for the unicorn. The INEXPENSIVE/CHEAP (big one there), 100 Watt, Dual band VHF/UHF radio. If I wanted to look for 5 seconds, and pick the most expensive option I found, I would have stopped at the Yaesu ftdx101d. But I'm not ashamed to used cheap Chinese crap. I'm not looking to spend $3500. I'm looking more 130-400. For watts, I know it's realistically more 60/70- 100, not a real 100. Dual band is preferable. But UHF is more important.
Thank you for all advice given. I know GMRS is 50 watts max. I know whatever it is I'm looking for isn't a GMRS radio. I know what I'm looking for classifies as a ham radio. Please sad hams, I've already taken the beating! Thank yall!
Since this is just "theoretical post and for speculation" and Ham related. For GMRS I'm sure you're well aware of the rules so it's up to you what you do.
I'm not aware of any "Ham" single or dual band radios for VHF/UHF that will do 100 watts. The most common power levels are 40 to 50 watts, with UHF generally being the lower of the two. Now for commercial mobile radios there are some that will do 100 watts. You'll likely end up spending a huge pile of shinny coins to get one.
You might be better off getting something in the 15 to 25 watt range. You can find these at relativity affordable prices. The following is an example of one I have. While it's an analog/digital radio I didn't complain about the price, It was free, pulled out of service after a short while, never reused, and scraped off the books by the original agency that had it.
https://forums.mygmrs.com/gallery/image/250-nx-820ghjpg/
The lower power radio you can later add the amplifier if you find it necessary. If your operations will be primarily through repeaters that's likely all you'll need. When I first got licensed I used a dual band HT on low power running into a Mirage dual band FM amplifier, around 35 to 45 watts depending if it was UHF or VHF. Never seem to need more for repeater use operating mobile. Later I had an Icom IC-706MKIIG. I almost never ran more than 20 to 25 watts on it either.
Generating the kind of power you want at UHF isn't that easy and it's not going to be cheap.
https://www.dxengineering.com/search/part-type/vhf-uhf-amplifiers/rf-output-maximum-power/100-watts
Most people coming to GMRS from a CB background are hung up on the power output myth, the more the better. At VHF and more so at UHF the communications are LOS, line of sight, the radio waves don't bend around obstructions in the path very well.
To give you an idea of just how far you can reasonably expect is look at a mobile antenna on a Jeep for example up maybe 6 feet. The range to the radio horizon, square root of antenna height above ground in feet times 1.4 gives range in miles.
sqrt(6)*1.4 = 3.4 miles
https://www.hamuniverse.com/lineofsightcalculator.html
If the other vehicle is about the same then it's the combination of both, about 6.8 miles. Running a huge amount of power won't extend this much. Some of the other posters here have done the experiments and have come to about the same conclusion.
-
1 hour ago, davidotoole said:
Yes. Thank you for clarifying this. My imagined commercial use involves communicating between employees, paging and finding one another on site. No advertisements or common carrier.
Each employee, including you, would be required to have their own GMRS license and comply with all the regulations including the ID one. As a business owner you can't get a license for your business, that was eliminated with the rule changes in 2017, and hand out radios to your employees.
If that's too much to deal with then just go and buy a bunch of FRS radios. Most of the same regulations apply that you see for GMRS. The big differences are the radios are limited to 2 watts on most channels, no repeater access and no ID/license requirements.
-
On 3/17/2023 at 10:47 AM, muggz said:
I put a spare (Diamond) 1/2 wave 2m/70cm mobile antenna on my Chevy Bolt with a hood lip mount and was surprised and happy to get ~1.3 SWR on GMRS as measured by my fars-o-meter 2000.
What model was that? I'm still looking for a mobile dual band antenna, 1/2 wave - ground independent, that's usable on MURS and GMRS as well as the Ham bands.
I thought the Diamond SG7500A would, but it isn't going to work based on my tests. On the Ham bands it looks OK.
https://forums.mygmrs.com/gallery/image/283-sg7500a-swr-scans-2jpg/
-
6 minutes ago, Sshannon said:
Clearer, perhaps, because of signal to noise ratio, but I have never heard anyone tell people to turn up their power if their audio is simply low. We’ll tell them to turn up their mic gain, or maybe engage compression, or to speak more directly into the microphone.
That's the usual reason, you're correct on that point. FM receivers incorporate a "limiter" stage for the sole function of eliminating any amplitude modulation in the RF signal.
Motorola software
in General Discussion
Posted
I guess you didn't read my post carefully enough. It's not the cost that's an issue, it's the usability. I've read about too many horror stories where people have paid their money, had a hard drive crash and lost the software and no means to deactivate the license since that required a functioning hard drive. Apparently this even happen to one person and it was the radio programming software that crashed and somehow wiped out the license authorization. Trying to get Kenwood to reissue a license or simply deactivate it on their end was nearly impossible and for some it was. They had to spend another $150 more or less to get their software to work again. The hassle and expense is entirely due to Kenwood's licensing. I'm not going to deal with that.
If all they were worried about was recouping their cost for development then just roll it into the cost of the radios sold and give the programming software away. They do it for the Ham stuff. However this isn't their goal. What they want to do is force end users to their dealer network for tech support and radio programming. Makes the dealers happy, more business means more money for them. In fact some unscrupulous dealers will program radios with read and write passwords and keep those secret knowing that if the owner of those radios ever got the programming software there would be noway they could make changes to the programming. Of course somebody will point out it's to prevent the owner from unauthorized changes, well they own the radio, it's their license, they screw up it's their fine to pay the FCC. The dealer is not an enforcement arm of the FCC.
There are other forums where it's a frequent occurrence for people to ask for software cracks/patches/engineering keys to remove these passwords. Myself I ended up with several used radios in just this condition. In one case I spent over a month searching for a patched version of the programming software to unlock the radio. I ended up buying it from a source in Mexico of all places.