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Rover83,
I have used those antennas in the past with external radios, but not with internal radios (and also not in my current situation). I’m glad you chimed in with your experience. I would consider trying that as it’s not too much cost and not that much more equipment to haul/setup.
I finally tried “listening in” on the GPS radio frequency I’ve been using by way of a handheld 2-way radio that’s tunable to nearly every useable frequency (Baofeng uv-5r). I’ve been on a large job way up in the sticks where I’ve not expected any radio interference. At the end of my survey, with my base off, I was hearing something that led me to believe my frequency wasn’t a clear one (kind of a pulsating noise). I randomly tuned the radio to a different frequency and made sure I didn’t hear the same thing (that frequency sounded clear). I then kept the 2-way radio handy during my drive home from the site and randomly checked it. I was hearing that interfering sound everywhere, including at my house about 25 miles south of the site! I’m wondering if there is something using that frequency county-wide? I think I need to change the frequency I’m using and monitor it more closely for awhile. I think that’s my due diligence before I conclude we need to get rid of these units. I’ve never had this issue in the past, but perhaps I’ve just happened to choose a bad frequency.-GarryUPDATE: I finally took the time to monitor the radio frequency that I??ve been using (by way of a simple cheap Baofeng UV-5R 2-way radio) and discovered that there is something on that frequency that at the very least covers the entire eastern side of the County where I do most of my work. The sound is best described as sounding like a machine gun and it??s constant. That frequency was 462.125. I changed the GPS system over to 462.400, which sounded clear, and GPS radio performance increased drastically. I did a little range testing on a particular job site where I was getting pitiful performance (2,800 feet, with open clear line of sight to the base being on the fringe of reception) and I was able to go as far as 8,900 feet away from my base and hold radio steady (at 10,000 feet the radio would come in every now and then, but wasn??t steady enough to ??fix?). That 8,900 feet was through a good bit of woods and over some slightly rolling terrain. I did purposely test going over the other side of a ridge (which would have also been through woods) and was surprised to see that I could still get radio in spots ?? in other words, the radio will go over a hillside to some extent, but don??t expect to go too far over a hill. In my 14 years of operating GPS radios, I??ve never been in a situation like this. Radios either showed interference right off the bat (i.e. trouble fixing right beside the base) or went their full expected range. I guess maybe I just happened to be lucky with my frequency choices in the past and unlucky this time. Lesson learned ?? the Baofeng radio is cheap enough and small enough to carry at all times to monitor the frequency in use, so there is no excuse! I can NOT recommend the Baofeng radio enough! Every GPS radio user should have one! If I were a survey equipment dealer I would package one with every system I’d sell.
-Garry
A quick search shows that the Alliance Sanitary Landfill near Taylor/Scranton has 462.125 among their licensed frequencies. Not sure if that’s close to you or not.
.I’m mostly in Indiana County, so no. I did a quick search myself, but didn’t find any licensing for 462.125 in Indiana County. I’m wondering if the “machine gun” sound is a repeater (whether for voice or data). I’m wondering if a repeater would be constantly transmitting even if there is no “input”?
-Garry
Gary,
I was browsing this forum cause I haven’t been on it for a couple of months. I came across your SP80 topic. After reading your conversations I’m really curious if you did trade in/sell your SP80? Our company has 2 base and rover packages and are thinking about trading them in cause of issues.
We have had them for 3 years and have already invested about $11k in repairs, mostly cause of antenna issues.
I currently use the SP80 now and message type I use is “ATOM”. Some days (once a month) I have to change type to RTCM 3.2
I also read your thinking about going to Carlson BRx6+. We currently have 4 base and rover set ups, 2 on external radio for bigger tracts. The crews love them, mostly cause they don’t have to troubleshoot them like they were having to do with the SP80s.
I also run a Trimble R8-3. The SP80 does blow the R8-3 out of the water as far as fixes in tree covered. We are now thinking of trading in R8 for R10s cause we have had no “repair” issues with Trimble units.
Again, hope to hear from you about what your running with now.
Thank you.
Machine Gun Noise: usually a SCADA system used for utilities. In my area mostly water districts synchronizing storage, pumps and valves.
Inexpensive Handheld Radio for monitoring frequency: Yes, absolutely worth it. We used to include the BaoFeng radios with all UHF receivers, but there was a ‘small’ licensing/sales issue with the FCC and we decided to stay completely out of the loop. Here is an Amazon [ link ]
Remoting the Antenna: The rubber ducky antenna that comes with the SP80’s (and many other receivers) is a 1/4 wavelength antenna and requires a ground plane at it’s base. The inside of the SP80 is spray painted with conductive paint which combines with the heat sink on the radio to make an effective ground plane. If you move the supplied antenna to the top of a cable, you must have more than the wire and connector.
If you google “does a 1/4 wavelength antenna need a ground plane” you will find plenty of detailed information and calculators.
If you choose to use the supplied 1/4 wavelength antenna, you should build a radial wire ground plane or use something like a pie plate.
However, I would switch to a 1/2 wavelength transformer matched end fed dipole which has been ‘cut’ for the center frequency of your licensed radio frequencies. We use a custom ProCom 5 db whip antenna (PN 140000182) with center frequency 462.888 MHz and TNC that I recommend. About $45.
@victor: Since changing the radio channel to one that is clear I’ve been able to make do with them. It’s too much of a loss (financially) to trade them in or sell them in order to upgrade to something better and this year isn’t going to be a great financial year for doing it either. Since we’re getting by now, my boss also didn’t want to invest in the external radio either. I’ve pretty much abandoned the idea of routing an external antenna to the SP80’s internal radio as I don’t think that would give enough boost in performance to be worth it. (I’m curious to hear more on if that is worth it though.) Most of my work is small surveys where I don’t need tremendous range.
Victor, if you’re having success with the Carlson BRx6+ units, why buy the R10’s? Is that only because of possible trade-in deals with Trimble?
@Mark: Thanks for the info! Yeah, I kind of knew I wasn’t doing things proper, but was also trying to test on the cheap! Pie Plate eh? Hmm . . . . Seems one of the biggest issues I had with choosing an external (no ground plance req’d) antenna was that I needed to switch over to the NMO mount which req’d a cable that was a bit expensive. I’d be curious to see links to a TNC connected antenna option (a no ground plance req’d antenna, or ground plane provided).
-Garry
I second this option, one of those 1m ish aerials on a 5m pole works wonders for rtk range on the satel radios that Lecia/geomax use and the old R8 I started on as a graduate had a specific elevator type tripod we put under it.
Also putting your base on the highest hill around and then doing a calibration on a control point helps to rather than just sticking the base on any control point.
NMO Mount not needed.
We probably should advertise these more actively:
https://iggps.com/iGA/iGA_UHFWhip.htm
Super high quality manufacturing, good reviews from customers, highest gain and best impendence matching I have been able to find. I order them cut to the center frequency (462.888 MHz) of my personal FCC license to boot.
They probably have 5 dB gain over the 1/4 wavelength antennas that you may be using now with a ground plane. (Every 3 dB doubles the signal.) Without a ground plane (on the end of a cable extension in free air) they will be orders of magnitude better, there is an SWR graph at the link that compares them to 4 standard antenna. (Antenna C is the SP80 antenna; antenna D used to be distributed with the SP80, PM500, PM800. Antenna A is the antenna we provide with the iG8 and is very common on most China origin receivers. Antenna B is the Laird antenna that we used to sell as a replacement for A.)
Elevation always beats power because of the Fresnel zone, so any power lost in the cable and connectors (up to some reasonable length) is offset by the increase in elevation.
@gbunk stock antenna eh? We use an external antenna (14″) on 12′ pole and get 2000 to 3000 ft range thru thick forest. cannot recall the radio settings. Using what dealer recommended.
We see broadcast range diminishes alot in thru a wet forest. The SP80’s do well in canopy, where our R8’s and Epoch50’s will not acquire a fix.
My only complaint w/ the SP80’s is the body housing. Very cheap. My kids Star Wars toys were more robust.
Hi…the radio has a coaxial 50-72 ohm input, which emphatically proposes it was intended to coordinate a dipole as the manual recommends. So the inquiry reduces to, would you like to utilize this fundamentally on one band, and in one transcendent direction, eg. north/south or east/west? Provided that this is true, a dipole built for the band of interest and arranged properly (dipoles are most touchy when the ideal sign shows up opposite to the wire) would be the best. On different groups and from different headings a dipole would be less compelling, so if mult-band, pretty much non-directional gathering is wanted, you would likely be in an ideal situation with a long wire. The manual says this is passable as well.
The HR-10B frequently gets compared to modest five-tube SWL collectors yet it is significantly in a way that is better than that. It has a 6BZ6 RF intensifier which is a similar cylinder utilized in the Hammarlund HQ-170 and HQ-180, the Heath Mohawk and SB arrangement collectors, and a ton of other first class radios. It has precious stone separating in its IF strip, which I think is its principle destruction; except if the radio is truly adjusted appropriately, for example the IFs are adjusted to the precious stones, it won’t function admirably. Obviously with regards to its pretty much passage level nature it is just single change and doesn’t have a different bandspread, however numerous hams combined them up with DX-60B transmitters as their first “genuine” stations.
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