Are analog lavalier systems obsolete?

QuickHitRecord

QuickHitRecord

Veteran
I'm at the end of my rope with RF wireless mics. A few years ago, I replaced all of my "illegal" frequency band Sennheiser G3s with "legal" G4s (both 470-558 Mhz). Since then, I've noticed more and more RF interference. It seems to be getting worse, as if the airwaves are becoming overcrowded. Nowadays, I can barely get through an interview without a couple of pops and waves of static. It's driving me crazy.

Here are some things that I have tried to improve the situation:
  • I scan for clear frequencies and use the recommended frequency.
  • I make sure that the selected mic frequencies aren't set too close to one another.
  • I use the squelch option to suppress any constant interference.
  • I've turned down the transmission power of both transmitters to the minimum available.
  • I ask everyone on set to put their phones in airplane mode.
  • I never shoot within 8ft of a modem or router.
  • I always make sure that the transmitter is within 20ft of the receiver (I do usually have the talent clip the transmitter to a belt, which may be behind them)
I still consistently experience RF interference. This was rarely a problem a few years ago with my G3s.

I also own four Deity PR-2s and two Sony ECM 77B wired lavs so that I can skip RF transmission entirely, but obviously these have their own drawbacks.

Has anyone else been having trouble capturing clean RF audio?
 
Yes, the airwaves are getting more crowded, especially in larger cities.

No, analog RF systems aren’t obsolete.

A couple of things to check for:

Just making sure “that the selected mic frequencies aren’t set too close to one another” isn’t exactly a guarantee for avoiding intermod. In fact, when coordinating multiple frequencies, you might be surprised to find out how closely some transmitters can be tuned without issues. I’m not a fan of the built-in clear scan on most systems. Rather, I carry an RF Explorer so I can see, in realtime, what’s in the air around me. I look for the best holes in the noise, and then use the FreqFinder app from NewEndian to select compatible frequencies. The app will calculate for intermod.

Which UHF blocks are more open differs from city to city. Where I live, for example, especially around our downtown, Block 21 is almost useless. There are other places where Block 21 is fairly open. It’s a good idea to diversify your systems to cover the entire, legal spectrum (470-608MHz, and Block 941 if you’re licensed for it). With the G4 systems, it’s good to have options between the A1, A, and G bands (EW100 systems) or AW+ and GW+ bands (500-series G4).

It’s possible to overpower the receivers if the transmitter’s power is too high. Though, with the G4 100 systems, adjusting the RF power isn’t an option. With the G4 500 systems, the options are 25mW and 50mW. Keep it at 25mW unless you absolutely need stronger TX power for distance coverage. Too much power too close to the receiver can actually cause an overload of received signal. The RX is going to regurgitate any excess, which can then bleed into a neighboring RX.

A common issue I see with G3/G4 users (and, to be fair, inexperienced folks using Lectro and the like), is with cable dressing on the TX. Be careful not to have the lav cable crossing the antenna, or worse, bunched/wrapped around it. They ground each other out and can cause a huge drop on RF output. Secure any slack in the lav to ensure it’s separate from the whip, or you can use a Viviana RF Saver to protect the whip. The RF Saver is also great because it is designed to keep the whip from making skin contact on the talent, which can also drastically reduce RF output.
 
Thanks, @Alex H. This is a very helpful response from a real pro. I've never used an RF Explorer before. I've been looking into them this afternoon but must admit that I am a little lost. It seems like there are multiple variants across multiple generations, some with paid firmware, and some with add-ons (extra antennae, etc). Is the basic WSUB1G what I should be looking for?

Also, if I understand your workflow, you look at the bar graph on your RF Explorer, find a frequency with the lowest bars, and then punch that frequency into the FreqFinder app to find a clean companion frequency (or multiple). After that, I'm assuming that you have to consult the RF Explorer again to make sure that the companion frequency has low bars? How many tries does this usually take?

I saw a video of someone who put his RF Explorer into a mode that would record the highest RF disturbance over a period of time (Max Hold). As soon as he got to set, he would let the Explorer run for 5-10 minutes before attempting to ascertain where the clear frequencies were. Is this something that you do as well? I've noticed in my own recordings that often a frequency will sound clean until we're 30-60 minutes into the interview, and then I'll start hearing bursts of static.

I tend to conceal lavs with Ursa foamies and wig tape. I try to coil up the slack close to the transmitter, but it's possible that the wire is making contact with the antenna. I'll take a look at that RF saver.

Lastly, have you run into situations where wireless dual-band video transmission has resulted in RF transmission? That's definitely something that I wasn't using 5-10 years ago, but I have at least one on ever shoot nowadays.
 
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QuickHitRecord said:
I'm at the end of my rope with RF wireless mics. A few years ago, I replaced all of my "illegal" frequency band Sennheiser G3s with "legal" G4s (both 470-558 Mhz). Since then, I've noticed more and more RF interference. It seems to be getting worse, as if the airwaves are becoming overcrowded. Nowadays, I can barely get through an interview without a couple of pops and waves of static. It's driving me crazy.

Here are some things that I have tried to improve the situation:
  • I scan for clear frequencies and use the recommended frequency.
  • I make sure that the selected mic frequencies aren't set too close to one another.
  • I use the squelch option to suppress any constant interference.
  • I've turned down the transmission power of both transmitters to the minimum available.
  • I ask everyone on set to put their phones in airplane mode.
  • I never shoot within 8ft of a modem or router.
  • I always make sure that the transmitter is within 20ft of the receiver (I do usually have the talent clip the transmitter to a belt, which may be behind them)
I still consistently experience RF interference. This was rarely a problem a few years ago with my G3s.

I also own four Deity PR-2s and two Sony ECM 77B wired lavs so that I can skip RF transmission entirely, but obviously these have their own drawbacks.

Has anyone else been having trouble capturing clean RF audio?
Click to expand...
Yes. It's getting worse everywhere. London is shocking. Just in case you are experiencing intermod problems between the (North America) 470 MHz frequencies you are using, regardless of wireless brand, just check them against the groups listed in this chart, link below. The frequencies listed in each group won't affect one another. Generally, it ranges between 8 and 16 compatible frequencies that you can run within any group without them affecting one another. Sometimes I have found I have to move some groups away to a totally different grouping of frequencies to avoid interference from external sources. In some cases I have placed the receivers, clipped to a couple of chairs or even on boom poles and placed those chairs, poles just outside the camera or cameras shot framing. Then run 2-3-4 or whatever meters of cable from those receivers to the camera or mixer position.

Chris Young

Are analog lavalier systems obsolete?

I'm at the end of my rope with RF wireless mics. A few years ago, I replaced all of my "illegal" frequency band Sennheiser G3s with "legal" G4s (both 470-558 Mhz). Since then, I've noticed more and more RF interference. It seems to be getting worse, as if the airwaves are becoming overcrowded...
www.dvxuser.com
 
I smiled at the notion of turning to lower power. This is kinder to OTHER users, but a killer to your system. Much depends on a really good knowledge of how RF behaves in crowded spectrum. Nothing to do with digital either, being honest. Digital hides issues, but they are still there. You just get silence instead of hissy, or nasty audio.

More and more people are paying for TV channel access via OFCOM.

Scanning is a really poor tool. It assumes other users you are unaware of, are operational. Most times, we sound check, then switch off to save batts. When you scan you have clear channels, ten minutes later you switch off, another local user does the same ten minutes later. At show time you are both on!

Scanning also wrecks resistance to intermod interference. Co-channel interference is VERY different to intermod interference. This is why Sennheiser and others give you those frequency charts that give you very clear channels to use. Finding interference on one, and then moving it it extremely risky. Solves co-channel, but increases intermod. I see people setting frequencies at random, then moving them about when they hear issues. Different types of interference sound quite different too, so determining what you are hearing is an important skill. Little devices like the RF Explorer, or a hand held scanner let you listen. If you hear digital buzz or voices, they tell you what is going on. Your system with pilot tones and gizmos prevents you hearing other users, you need the opposite.

Over this summer I have been watching visiting shows arrive with everything using RF. every mic and instrument using RF and every musician has individual channels of RF for their in-ears.

In almost every case transmitters AND receivers, often in the same band, are in the same rack. This is stupid and really very often the cause of issues. With metal cases to the gear, thats no the killer, but transmit and receive antennas in the same band, close together are destructive. A receiver looking to get as much RF from that distant stage transmitter gets desensitised by strong signals closer in distance and frequency. You see IEMs and transmitter packs all randomly using frequencies in the same band. A radio pack on the guitar strap, and an IEM pack in the players pocket. The guitar can make the IEM receiver swamp, and they lose their monitor feed. Sometimes you see a stage side antenna right next to the other diversity channel antenna. Totally wrecks the entire idea of diversity. When a stage has a ‘black hole’ for RF. There always seems to be one. This danger area relates to transmitter and receive antenna path. A second antenna in nearly the same place has nearly the same path. Move the second antenna a meter/yard or two, and the black hole for that path is different, increasing safety as diversity operation is brilliant. But it needs space to work properly. In the West End and on Broadway, no show would think about running without a dedicated audio person on stage who nurses systems through each show by constantly listening and spotting issues as it is not really an equipment thing, just a physics one. Frequency planning and coordination is a skillset. Rocking up to a new venue and turning the gear on without proper thought Is a real risk. Last week one show turned up and had issues. Is there anybody local using radios? The theatre is on a pier, no other users. The snag was pretty clear to me, watching their tech guy randomly scanning and changing channels, as he clearly did routinely. Every change has a knock on effect they probably never discover till they play the first number on stage.

Digital on the normal frequencies has exactly the same issues that are hidden until the kit says enough is enough. Digital on 2.4 or 5 GHz is often better, but of course is VERY unfriendly to all those ipads sound and lights use to wander around, plus the thousand folk in the audience who were not there during soundcheck, who all have their wifi turned on!

RF is magic. Or at least, a real nightmare ten seconds from auto-destruct.
 
I've replaced RF Explorer with TXAdvance. It is an app that uses an SDR dongle. It does the scan, determines where to place your transmitters based upon intermod spacing and what it found in the scan. It does a lot more than that, but that's all I use it for.

Getting started - TXAdvance

Download the TXAdvance getting started guide (pdf) Download the TXAdvance user manual (pdf)
www.compasseur.com www.compasseur.com

 
QuickHitRecord said:
Thanks, @Alex H. This is a very helpful response from a real pro. I've never used an RF Explorer before. I've been looking into them this afternoon but must admit that I am a little lost. It seems like there are multiple variants across multiple generations, some with paid firmware, and some with add-ons (extra antennae, etc). Is the basic WSUB1G what I should be looking for?

Also, if I understand your workflow, you look at the bar graph on your RF Explorer, find a frequency with the lowest bars, and then punch that frequency into the FreqFinder app to find a clean companion frequency (or multiple). After that, I'm assuming that you have to consult the RF Explorer again to make sure that the companion frequency has low bars? How many tries does this usually take?
Click to expand...

Yes, just get the base model that scans 240-960MHz.

I watch the scan for a few minutes. Typically, you’ll see chunks of available space in the scan, and I’ll note those with a low and high frequency bookending any decent opening. One thing that can cause intermittent issues is TV, so it’s good to know which frequencies in your area are being used by TV transmission. That can be found in publicly-available frequency finders online.

Once I know where my available space is, I start a new profile in FreqFinder, and I’ll pick a clean frequency that’s on the upper end of my available space. I’ll tune that system, then leave it running while I use FreqFinder to add a second channel and select a compatible frequency below the first one. I’ll tune that second system and leave it running while I repeat the process for the third channel, and so on.

It’s important to listen to your systems as you work. If you fire one up on a newly-selected frequency and it causes issues with one of the already-tuned systems, you’ll need to back up and try again. This is sometimes referred to as “war gaming” your systems.

One great feature of frequency coordination apps is that you can specify which system and which band you’re using, it it will calculate compatible frequencies based on that system’s (or those systems’) deviation specs. That’s also helpful if you’re trying to frequency coordinate multiple channels that also include systems from different manufacturers.

QuickHitRecord said:
I saw a video of someone who put his RF Explorer into a mode that would record the highest RF disturbance over a period of time (Max Hold). As soon as he got to set, he would let the Explorer run for 5-10 minutes before attempting to ascertain where the clear frequencies were. Is this something that you do as well? I've noticed in my own recordings that often a frequency will sound clean until we're 30-60 minutes into the interview, and then I'll start hearing bursts of static.
Click to expand...

Extended scans with peak hold can be helpful, especially if interfering sources are intermittent. Paul also mentioned TXAdvance, which is a super-helpful tool, as is Wireless Designer from Lectrosonics. For my personal use case, most of the time, I’m running with a bag or a small cart, and using a laptop isn’t practical. These apps aren’t available for iOS, which I’m using with both iPhone and iPad, because iOS devices aren’t capable of RF scanning with an antenna dongle attached (at least, not yet, but I can’t remember if it’s a hardware or OS limitation). So, the RF Explorer is a compact solution that’s easy to pack and easy to deploy, and the FreqFinder app does a great job of coordinating frequencies.

QuickHitRecord said:
Lastly, have you run into situations where wireless dual-band video transmission has resulted in RF transmission? That's definitely something that I wasn't using 5-10 years ago, but I have at least one on ever shoot nowadays.
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Sets are getting more crowded with everything from UHF to WiFi and Bluetooth. Anything that emits RF has potential to interfere with other things that emit RF. I’ve had walkie talkies on set, operating the 460MHz range, spilling RF all the way up to 485MHz. While I haven’t really had issues with wireless video links mucking up my systems, I’ve heard several other mixers mention it.
 
In my experience I've had no RF issues and I shoot theater musicals 100 ft away, where's there 20 kids on stage with wireless mics and an auditorium full of smart phones. For interviews if there's only 6ft in between the transmitter and receiver the most like source of interference is the subjects phone that's inches away from the mic, wire, and transmitter. On that point some mics do a better job of rejecting RF, the Sanken cos-11 comes to mind.

For interviews, I use wireless lav as backup to the boomed shotgun mic because dislike the sound of lavs.

For legal work I use wired lavs which are a pain but the provide rock solid audio which is the only thing that matters in that application. But even wired you have to keep power bricks and adapters away because those emit a powerful elector-magnetic field.

I'd either go wired lav or boomed mic for stationary interviews.

Like Paul said an RF scanner will actually show you what's going on. Although I find it better eliminate the chance of an issue rather than spend time I don't have troubleshooting it.

​

 
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paulears said:
I smiled at the notion of turning to lower power. This is kinder to OTHER users, but a killer to your system.
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Paul, I have to disagree here. And the wireless companies, like Lectro, will say the same. But I think we’re talking about two different things here.

It seems you’re speaking from a live venue perspective, which is going to be an RF nightmare far beyond what we see on a typical film or TV show. What we’re usually up against is just a crowded 470-608MHz band due to urban density, and some interference from neighboring bands and the cluttered 2.4MHz and 5MHz bands.

In a typical production sound setup, either bag or cart, the reality is that higher-power transmissions can and will overwhelm the receivers and cause massive RF issues in close proximity. In the original post from @QuickHitRecord he notes that he’s keeping within about 20’ of talent. 25mW should be more than enough to maintain a healthy link and stay above the noise floor (assuming properly-chosen frequencies).

You always want to make sure that your RF link is at least 20dB above the noise floor, but you don’t want to have too much power in too close a proximity. Try operating a Lectro transmitter at 100mW within a few feet of the receiver. You’ll probably have a terrible time of it. I’ve experienced this, just on powering things up at the start of the day and having transmitters sitting near my bag.

And yes, if someone else shows up and tries to fire up a system on a frequency already in use by another system, chaos ensues. But that doesn’t negate the fact that intermod is a problem, and it’s one I see quite often with inexperienced wireless users on set/location. This is why the coordination apps are so useful.

paulears said:
Scanning is a really poor tool. It assumes other users you are unaware of, are operational. Most times, we sound check, then switch off to save batts. When you scan you have clear channels, ten minutes later you switch off, another local user does the same ten minutes later. At show time you are both on!
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Again, I don’t think that’s correct. And again, this seems to be more from a theater/venue POV than from location/set.

Most large venues here in the US - stadiums and arenas - have RF coordinators on staff who are the final say in who gets to run which frequencies. The show, or the football game (and its broadcast) take priority, and anyone else wanting to come in must register and be assigned frequencies. People who just show up without getting prior clearance will be shut down. And large conventions, like NAB? Forget it; those are RF anarchy.

And one of the shows I’ve mixed for several years has a companion series that sometimes shows up on set to get pickup interviews with their talent. They bring their own wireless systems. I have always required that they check in with me first, and I will give them a clear and coordinated frequency to use.

Another anecdote: I worked on a show that had terrible RF issues. The gear would come from out of state, and would be packed with a list of “coordinated” frequencies that was generated by a piece of software based only on FCC records of TV stations and reserved frequencies. It was not made using a site scan. Worse, the freq set was coordinated as if two audio bags would be running in separate directions, rather than operating in the same space. One day, I plugged all the frequencies into the FreqFinder app and showed the supe. All but two of the frequencies had intermod hits, and most of them had multiple conflicts. That’s when I convinced him to let me re-coordinate the show. I did, using the RF Explorer and FreqFinder, and all the problems went away.

paulears said:
RF is magic. Or at least, a real nightmare ten seconds from auto-destruct.
Click to expand...

On that, we can agree.
 
I totally get the point about power, but only really agree on the benefit in certain circumstances. If you are in an RF sparse environment, then removing the risk of oversaturation makes sense. Its interesting though that some makes seem to cope with this better. Most of my video work is indeed in entertainment. Lectrosonic i cannot comment on, because even though we do see it here, as a brand, it’s not a product i have ever owned myself. It does seem odd they have not designed in the capability to cope with strong RF on, or off the selected frequency? Frequency coordination is a critical component, but my role for the past few years has included policing the TV guys, who arrive, fire up their gear with absolutely no interest in our system. I always try to quietly see what channel they are on, many times its in the same band we have a working, coordinated and pretty solid system working, but with many transmitters turned off. They always assume that frequencies in use are always active. They are not.

If the game is rock solid RF performance, then signal path loss is the real number one issue. Drop outs and avoiding them is the main problem. Receiver desense from other sources close to them is made worse if the remote wanted transmitter has lower power. Trouble is, agreeing with Alex, when that unit gets close to a different receiver, it causes the same issue to another user. I haven’t put my Sennheisers on an analyser, but the receivers dont seem to suffer from over strong RF sources to any degree. Either on frequency or off. You can make them deaf with a transmitter on a close frequency, but with inverse square law, even a bit of distance restores normal operation. Are Lectrosonic designed with audio quality leading RF performance. As in the wrong balance between sensitivity and selectivity? Changes in audio quality with strong RF seems a strange design flaw?
 
When I have run into frequency problems, even when we have been allocated frequencies for RF congested major televised sports events or somewhere like Sydney Opera House, where frequently they may have 180 wireless sets running at any one time, We usually use a few sets of Lectrosonic "NATO" SNA600a adjustable dipoles. Spacing our antennas to get the best results. I can't remember them ever letting us down. Don't ask me why they are referred to as NATO?

If the receivers you are using do not have SMA connectors, like a lot of the Senny and Sony units, you are out of luck unless you get them modded for SMA connectors. I was put onto these 600s years ago when having issues on a job. A soundie at the job said, "Here, try these." I left that shoot totally convinced. The range increase and interference rejection from other sources using these units have never ceased to amaze me on numerous occasions. They are small, light and just work. Just take a bit of time frequency tuning them and placing them, and you are good to go. Frequently we will have around about three meters between the ANA600 units, sometimes more.

Here is some feedback on them and a link to them for those who don't know them.

Chris Young

https://jwsoundgroup.net/index.php?/topic/3556-lectrosonics-sna-600-antenna/

The Antennas

https://lectrosonics.com/wp-content/uploads/filr/3603/sna600atd.pdf

Modding Sennys

https://stevenoakley.com/adding-an-sma-antenna-to-your-sennheiser-g3-or-g4/
 
I know it’s not “best practices” but for solo operation, just go bodypack recorders. Skip the transmitting and receiving. Learn good lav mounting techniques, these days there’s all sorts of great options. I use the Viviana beetle system. Love it.

The less gear the better. Less complications equals more energy spent on more important tasks than pressing buttons.
 
Movies by Matt said:
I know it’s not “best practices” but for solo operation, just go bodypack recorders. Skip the transmitting and receiving. Learn good lav mounting techniques, these days there’s all sorts of great options. I use the Viviana beetle system. Love it.

The less gear the better. Less complications equals more energy spent on more important tasks than pressing buttons.
Click to expand...
The original poster said he has wired lavs and a recorder Deity PR2.

The issue with recorders your not monitoring what's being recorded. If you're concealing the mic there's always a chance of clothing noise developing. I find when monitoring with head phones you're more apt to pick up on environmental noise issues or how the person is talking.

He also said these are for interviews so I don't think the broadcasting situations described by other posters apply.

Like I said the wired lav is the simplest solution.
 
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paulears said:
I totally get the point about power, but only really agree on the benefit in certain circumstances. If you are in an RF sparse environment, then removing the risk of oversaturation makes sense.
Click to expand...

And in my production world, I’m not typically in an RF-saturated environment, not counting whatever is crowding the city airwaves. I’m on a set or at a location where I’m the only wireless user, so it’s up to me to ensure proper RF coordination to avoid intermod, and to keep TX power managed. When I’m out in the field and running from a bag, it can be a challenge to find clean frequencies out on the streets in the larger cities. Atlanta, for example, is an absolute nightmare. So are NYC, Chicago, and LA.

paulears said:
If the game is rock solid RF performance, then signal path loss is the real number one issue. Drop outs and avoiding them is the main problem. Receiver desense from other sources close to them is made worse if the remote wanted transmitter has lower power. Trouble is, agreeing with Alex, when that unit gets close to a different receiver, it causes the same issue to another user.
Click to expand...

Again, we’re coming at this from two different scenarios. Theaters and entertainment and sports venues that run dozens of channels have to be wary of outside people (news crews, etc.) showing up and firing up their own wireless an unwanted and conflicting frequency.

For me, when I’m on set and have 16 channels to coordinate, I’m not up against all that, just up against my 16 channels. I’m also going to make sure all transmitters are at the lowest power setting possible to keep a healthy link, and that they’re all at the same power. I was on a show last year, shooting in a warehouse-turned-temporary-set, and had asked that all transmitters (Lectro SMDWB) be set to 25mW as we were setting up and tuning everything. I was told they were. The war game went fine, but once we started into production I started having problems with a couple of the channels on the show’s hosts: signal was unstable and I kept getting little RF hits and fizzles. I’d also noticed that battery life on those transmitters was unusually short. So, I checked the units and found they were at 100mW. They weren’t causing issues with other channels, but they were overpowering their own receiver channels at less than 50’ away. Once they were dropped back to 25mW, all the issues went away.

And keeping solid RF is a multifaceted process:
- Proper RF coordination to avoid intermod (and, if necessary, to find clean freqs for outside users visiting the location or venue).
- Transmitter power management to make sure no one transmitter creates issues for itself or for other channels.
- Proper transmitter placement, avoiding crossing lav cable and whip and keeping the whip from skin contact.
- Antenna management to keep the best line-of-sight link from transmitters as possible.

And antenna distro that consolidates multiple receivers to a single pair or dipole is a huge help on set. This allows flying an antenna mast, since height helps ensure a less inhibited pathway from TX to RX. In the case of an audio bag, using RF distro to run a pair of fins or butterflies on magic arms outside the bag also removes the antenna from RF emitted by equipment in the bag (some mixer recorders are worse than others, but they’re all computers that have RF spray in their immediate vicinity).

I may be making assumptions here, but I think the original question from @QuickHitRecord pertains more to location production than to working in large venues.
 
going back to post 1, quick record was frustrated with not being able to get through an interview without pops and ‘static’. It’s quite possible that this could be nothing to do with other wireless mic users. I have one receiver that is faulty. It is a bit deaf, and has thwarted all my attempts at fixing it. Probably 10dB down. However, so many things can cause even a pretty short path to fail. I can’t speak for the US, but in the UK everyone should be using channel 38, which has no TV channels in it. Years back, we had channel 69, but this was reallocated to TV use in some areas, and while where I live and work, it is empty, in other places it is not, and using it for audio produces very strange effects. Channel scanning finds an empty band, because they scan for other radio systems and find a TV signal quite difficult to detect. In most cases, you do not hear nasty buzzes with your tx pack off, you hear empty space. However, your receiver just struggles with the narrow bandwidth signal from your transmitter against a powerful, usually digital broadcast mess that is hiding in plain sight. The RF Explorers and other spectrum analyser type gear shows you the mess. Which resolves as huge spikes where there should be nothing. The other cause of dropouts is from other forms of RF that conspire against you. Lots of legal comms or data transmitters, but also so man6 illegal ones using frequencies that are legal elsewhere, but not where they are in use. Only recently i have got two types of spread spectrum comms systems that do not resolve on ordinary kit as the usual digital buzz saw noise. Normal radio receivers simply dont hear them, or react badly to them. RF explorers dont pick them out as anything other than an increase in random noise. They just seem to raise the background noise floor. The old rule that the most expensive radio system is nearly as good as a 10 pound/dollar cable is so true.

Dropouts come from signal loss over the path. People, obstacles and distance. However, they also occur due to the presence of other signals that to the receiver, are stronger. FM science has capture effect, as in the strongest signal wins with a very short crossover between perfect vs awful. RF also is susceptible to problems caused by sum and difference. Two frequencies combining into phantom signals based on maths. The most annoying problem. A broadcast signal mixing with a comms signal to produce a phantom signal on your wireless frequency. Or worse, two comms signals that wreck your system only when they are both transmitting. Analysers struggle with this because the interference only manifests randomly.

Switching to digital isn’t a cure for some of these issues, but does reduce others. For an interview, that has issues, lower RF output will make it worse, and careful frequency choice takes time. Sticking the analyser into peak hold takes time to build up a picture.

Always a gamble. Probably why many people here kept a few old channel 69 systems, just in case. Here, it is quite peaceful there! Illegal of course, but that is a different conversation.
 
Great discussion and almost enough to make one get out of the business! Seriously, this is so far away from "sound" that it takes a suitably brained person to master.
 
...and I’ll pick a clean frequency that’s on the upper end of my available space.
Click to expand...

I have an RF Explorer here now as well as the FreqFinder app. It all seems pretty straightforward, but I'm hoping that @Alex H. will explain the importance of choosing an empty frequency at the upper end?
 
QuickHitRecord said:
I have an RF Explorer here now as well as the FreqFinder app. It all seems pretty straightforward, but I'm hoping that @Alex H. will explain the importance of choosing an empty frequency at the upper end?
Click to expand...

I looked back at that post and realized I’d left out a bit of context: I tune from top down, rather than starting with the lower frequencies and tuning up. Not as much the order in which I select frequencies for FreqFinder, but the order in which I tune transmitters and fire them up in the war game. So, my first channel in my wireless rig will end up being the highest frequency. Not sure why, just the way I was taught a long time ago and can't find any hard data to back up why it's "the right way". Probably just a sad case of "because thats the way I've always done it".

It's also helpful to remember that every wireless transmitter has deviation, or the amount of space it actually uses on either side of the base frequency. The more frequencies you pack into a smaller space, the more the deviation above and below that grouping actually expands, so at some point.
 
Alex H. said:
I looked back at that post and realized I’d left out a bit of context: I tune from top down, rather than starting with the lower frequencies and tuning up. Not as much the order in which I select frequencies for FreqFinder, but the order in which I tune transmitters and fire them up in the war game. So, my first channel in my wireless rig will end up being the highest frequency. Not sure why, just the way I was taught a long time ago and can't find any hard data to back up why it's "the right way". Probably just a sad case of "because thats the way I've always done it".

It's also helpful to remember that every wireless transmitter has deviation, or the amount of space it actually uses on either side of the base frequency. The more frequencies you pack into a smaller space, the more the deviation above and below that grouping actually expands, so at some point.
Click to expand...

Thanks, @Alex H. I am very hopeful for this new workflow. I've been testing it at home but I've never really been able to recreate my RF woes here (go figure).
 
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