gman1971
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Posts posted by gman1971
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"Not expensive" and "long range" in radio usually don't belong on the same sentence. If you want long range out of UHF, be prepared to sped time and money.
As for antenna, the Laird FG-4603 would be my next choice if you don't want a folded dipole array, which I would strongly recommend. There is a Harvest 2-bay dipole available on eBay that might be a good compromise.
Manage expectations: 20 miles from base to a portable, reliably, and out of UHF GMRS will require a decent location, a tall tower/mast and very good antenna (which doesn't develop high SWR after 3 months of being installed), a good feedline (probably look into heliax 1/2" at the very least if you really need a 100' run). And a very good radio/repeater with a receiver that will not get overwhelmed when mated to a good antenna placed that high. Most likely you'll need additional filtering if you use low end stuff.
G.
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Well, the money has to be spent somewhere, either going straight with a Quantar that just works, or go cheap and then have to buy additional infrastructure just to make them sort of work... but in the end its all a matter of $$$.
I doubt the Quantar will ever have issues interfering other equipment due to missing Part95 certification. Most of these trash CCR repeaters, Retevis, etc, those even though they are Part 95, they are far more likely to cause interference with the rest of the tower equipment, or desense like cheap POS, or even catch on fire and bring the whole tower down... yep...
You buy cheap, you buy twice.
G.
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You do have a sharkfin antenna on the car, I would remove that and put an NMO there, then a simple 1/4 wave 6 inch whip will do the trick. No drilling. I've done that on two of my cars and it works perfect.
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Could be related to intermod in the TX. When some RF gets into your transmitter, the range drops like a rock...
- gortex2 and Radioguy7268
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Congrats!!, it sounds like you've reached the same conclusion I've reached as well. Motorola is not hype as they would have you believe, that is for sure.
Totally agree, experience wins a lot of contests, for sure.
@gortex2The only reason the "do it cheap crowd" gets away with their cheap stuff because guys like @JB007Ruleshave spent 5 figures on their repeater setup, so the overpriced pieces of garbage trash CCR radios have any hopes of working: Simple as that.
Well, I think depends on what 30 dollar radio you are talking about, but in general most cheap radios mated to a 1k antenna will desense really bad, so you'll end up with a deaf radio. You'll need to add several hundreds of dollars of filtering to the 30$ radio front end (or lack thereof) just to make it work.
I am certain the ISOtee on that Quantar is off-the-charts good... and all Kenwood radios I've ISOteed were not that great. Even the Vertex Standard radios were only marginally better, but there was a jump going from everything else to Motorola, even the 6550 receiver beats every Kenwood radio I've tested to date.
Tuning goes a very very long way (understatement here). as I've found that tuning the radios correctly can make the difference between 3 miles and 30 miles with ease!!
Given the cost of used Motorola gear, IMO, once your eyes are opened, there is no reason to ever go back to inferior equipment.
G.
EDIT: Forgot to say this (again), but there is a reason why the longest running, furthest reaching radios ever made by humanity are made by Motorola. Yes, the Voyager probes have Motorola radios...
been running non-stop since the 70s, and they are past the Heliosphere, or about 14.4 billion miles from Earth (as of 11/2021)... so, if you want range, think only Motorola (except the R7 turd...
) How far does your light shine?
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What is the intended goal for the radio?
G.
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That indeed sounds awfully wrong for shipping a few metal tubes...
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Yep, for UHF, for hilly terrain like yours (and mine) antenna height is usually the best way to roll, even 5 feet can make a difference...
Also, good equipment in the base side will go a long way too.
If there are commercial antenna towers nearby, then I would suggest getting at least 1 cavity as well. That will go a LOOOONG way with intermod (not only on RX, but also on TX too) and any potential desense.
G.
EDIT: I would also use RadioMobile, their algorithm usually lowballs the estimated coverage. I would take the average of the two. 40 miles on UHF with only 25' seems like an exception, not the rule. Also, if you plan on using this for personal equipment, for simplex, I would take @gortex2 estimation more like what you'll see, rather than that coverage map. In the end, nothing can replace you going with an RSSI meter logging the different strength signals at different points in the map, then comparing them with a site analysis estimated RSSI strength.
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40 minutes ago, marcspaz said:
I have a analog Swan power meter that I use for measuring peak AM/SSB power, upto 3,000w. It has a capacitive circuit that holds the peak and slowly drains off. That is the only meter I use for tuning my radios or amps. I use the Bird for legit engineering, bench testing and repairs. I only use my Diamond and Surecom meters for monitoring low power FM power and SWR for day-to-day use.
I'll make you laugh... I almost never use the Surecom unless I am looking for a "Wow!" factor for people who are new or know almost nothing about radio. People love stuff that lights up! LOL
Maybe you need the one I just sent back.. like someone said, it will boost your ego LOL......
G.
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Well, the Bird 43 is then... thanks!!
G.
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Looks like I'll be saving the money in the Aeroflex fund... maybe in a couple of years LOLOL.
G.
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16 minutes ago, marcspaz said:
To the best of my (very limited) knowledge, Bird does not make any watt meters with a digital display.
bummer... looks like in the end I'll have to shell the cash for a service monitor...
@wayoverthereYep, nowadays Amazon is also a crapshoot like fleabay... especially with these devices. you might get a good batch, you might not... I'll probably wait until this thing is returned and the money refunded... then we'll see...
Thanks!
G.
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Most ham diplexers I've tested were about 50-60 dB isolation. For most cheap radio stuff that could be a problem, since the receivers have no front end filtering, even when tuned to VHF, anything coming in the UHF could degrade performance.
For commercial grade radios, the 50-60 dB isolation U/V + the radio front end filtering should probably be good enough to get you by. Now, you can always use those diplexers with a preselector or a cavity, which will further reduce the signal so there should be no issues at all.
G.
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4 minutes ago, marcspaz said:
As I mentioned, I would replace the one you have. Not align it. I would never trust it because of how far off it is. To align the unit, there are a couple of different methods you can use.
The first method, which is the fastest, but least accurate way, is to compare it to a known good/accurate digital meter and simply use the menu adjustments. The other is to use a generator and dummy load to calculate the value and dial it in.
To use the second method, you are going to need a stable signal generator (+/- 2.5 ppm) that will operate at 0.5w, a VAO meter, and a dummy load and appropriate barrel connectors (don't use patch cables). You measure the resistive load to confirm it is indeed 50 ohms. If its not, make a note of whatever it is. Turn on the signal generator while connected to the VAO meter and dummy load, set the generator to 0.5w and measure the current and the voltage.
Use E/I*R and P/E*I to confirm all of the measured values are correct and to calculate your wattage. Then, replace your meter with the SW-102 and turn the generator back on. Go into the SW-102 menu and adjust the frequency to read correctly. I can't get SureCom to tell me what wattage we are supposed to calibrate to, so I just used 50w and that seemed to be a good number. From there, increase your wattage to 50w and adjust the voltage controls (forward and reverse/reflected power) as needed.
Be sure you have the USB cable connected as a power source while adjusting.
Probably right about that being so far off...
BTW, the seller accepted the return, so back it goes. Any recommendation for a decent digital Bird watt meter?
Thanks.
G.
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16 minutes ago, tcp2525 said:
Sounds like a keeper to me. You got a great "feel good" meter that is capable of boosting your ego as well as the watts. Perfect for the 11 meter enthusiasts.
I think I read it wrong... its certainly not a keeper, it belongs in the landfill... ah the good old CB.
G.
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2 minutes ago, mbrun said:
I concur on the ‘its a dud’ responses as well, and I feel your frustration. Fortunately G you are both wise and experienced enough to know something was wrong. The less experienced might have taken readings at face value for a long time.
I always question the performance of test equipment, especially the cheap stuff, and feel the need to contrast it with readings from other brands and models before I give it any form of credence.
Michael
WRHS965
KE8PLMWise is probably stretching it a bit too much... LOL, but thank you.
It sucks tho, me wonders how many people who get those things don't realize their SWR are probably flat out wrong...
G.
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7 hours ago, marcspaz said:
I would try exchanging it first. You definitely have a bad unit, but I think it's just bad luck. Also, the device is capable of being calibrated by the user. Once I calibrated mine, it's as accurate as my Bird 43, which is a benchmark product at more than 8x the cost of the SureCom SW102.
Got mine from eBay... I think that is where the problem lies....
So, how do I go about tuning this thing? I would like a small portable power meter that has a digital readout.... it is somewhat comforting hearing that it can be fixed.
Thanks.
G.
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I've always used a trusty old needle power meter to measure radio power... and its been pretty accurate so far, but I wanted something digital, etc.
So, I picked one of those just to see what the fuss was all about, at the time it seemed like a nice device, had digital readout, etc. I also keep seeing everyone in this board using one to measure stuff, so wanted to see first hand how accurate they really are, and potentially keep it.
Anyhow, first radio to be tested is one of my XPR5550e, placed it on the SW-102 meter, using a 50ohm dummy load, press PTT and... boom, my 5550e is now pumping 79W... hahaha.... I know the Motorola is calibrated to put 50W. Put a CDM1550LS? boom, this one is pumping 85W holy cow... I didn't know Motorolas were that good LOLOL. I then connect it to a Vertex EVX-5300? and same deal: 78w, another EVX-5300? same thing, 80W. Then take one of my XPR6550 with SMA, low power is supposed to be 1W, not for the Surecom, it reads 1.85W, another 6550, same deal, 1.79W. high power? 6.98W... its a 4W radio...
So I fire up the Antyone AT-578U/V just to see what is going on, the turbo mode yields 82W... Get the TM-V71a out mothballs? same deal, 79W. Basically, all my 50W mobiles read around 80W on this Surecom trash... that is super accurate.
Then the SWR readings are also off, it reads a WHOLE lot lower than the real deal. I have several VNA analyzers and all of them agree within a small return loss percentage... even my old trusty needle meter is more accurate than this POS.
Maybe its measuring using Cheap China waaatts, or waeetts, or maybe China Lumens like those 50000 lumen flashlights, maybe to make radios look better?... who knows, right? my advice after trying this turd is to dump it like a hot potato and get a Bird meter... or something else that is actually calibrated using standard Watts.
So, there you have it: buy cheap trash, expect piss poor outcomes.
Returning it as I type.
G.
- Luish19779 and WROZ250
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I would do a 2-bay or 4-bay side by side folded dipole in the attic.
https://www.ebay.com/itm/134023808353?epid=1941709490&hash=item1f34710561:g:yowAAOSwIytgUyhQ
G.
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Good radio choice, just make sure you get decent cable (heliax 1/2). Use N connectors if possible. I personally would chose a 2-bay or 4-bay dipole over anything Diamond made....
There are places like radiomobile.com that will do a crude site analysis for you. You punch the gain, the location, etc, and you get a coverage map. 25 miles in UHF is hard to achieve, especially in rough terrain.
G.
- Ronster and Radioguy7268
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That is not a good idea on a car. It will come undone at speed. Why do you want that antenna on a car?
Just use a regular 1/4 wave Larsen. Seriously, I am able to reach 30 miles simplex (no repeater) on my cars with a simple 1/4 wave Larsen antenna... Concentrate all the efforts in the base setup.
G.
Seeking guidance for my first repeater
in Technical Discussion
Posted
One thing to be aware with higher gain, is that your reduce the vertical beam cone, imagine a flashlight with adjustable focus: flood and throw.... so you get more throw, but then the cone of light gets narrower. So if there are a lot of elevation changes, it might be more detrimental than just running a lower gain antenna with a wider "cone of light"
G