Robert Rogers Sound Recording
Info and Frequently Asked Questions about my SMA modifications
What is the SMA mod?
The SMA mod is a popular modification performed on Sennheiser G3s. An SMA modified wireless receiver or transmitter performs better than stock, providing a longer range with far stronger signal stability and virtually no dropouts compared to stock. Further, the mod provides the convenience of a removable, flexible SMA antenna and the ability to connect the device to larger RF antenna systems.
Independent info about the mod on a Sennheiser G3 can be found here:
https://wavreport.com/2016/11/19/g3-sma-mod-range-testing/
Benefits of the SMA mod:
My SMA modifications generally make radio microphones 20-30% better because the original antennas are often too short, the stock antenna wavelength is often measured from within the chassis being partially insulated, they are made of very thin gauge wire and are often bent and degraded from general wear and tear – in some cases they are completely missing! Since I am not redesigning the devices, they still output the same amount of power.
The mod does not only improve measurable distance, it results in stronger signal stability that virtually eliminates all those regular ‘flick’ and ‘pop’ drop out sounds that can ruin a sound recording.
I have even found the mod to be beneficial to brand new Sennheiser G4 512p and have never seen a decrease in device performance after I have modified it.
The most impressive mod I’ve done was on a 3rd generation Sony UTX-B03. After SMA modifying this specific transmitter the range increased by almost double. It even outperformed my much more expensive Wisycom units.
While the improvement to the modified antenna will not be “true diversity,” nor will it have improved signal clarity for tests such as the “key test” or the ability to record locally, the mod is fantastic value compared to the approximate AU$5,000 cost per channel for the next step up in equipment (such as Lectrosonics/Audio LTD/Wisycom or Zaxcom), compared to about AU$750 new or AU$400 used for Sennheiser and Sony wireless systems.
Additional benefits:
The SMA mod also provides the convenience of a removable flexible SMA antenna for easy storage and the ability to connect to other standard SMA systems.
I sell SMA right angle adaptors for $5 which can come in handy when mounting a receiver to a camera. You can also invest in larger RF antenna systems and SMA distribution hubs but be careful to avoid over amplification as this can apparently cause damage. Larger shark fin style antennas should also increase your signal range dramatically.
More info can be found in the videos below:
https://www.youtube.com/watch?v=3UBUNxbT0JE
https://www.youtube.com/watch?v=ginZamnuo0k
Another benefit of the mod is that if your antenna is damaged, lost or destroyed on location, you can easily source a replacement from any local film equipment specialist such as John Barry’s or Lemac. I use the same SMA antenna type as standard on Lectrosonics and most other brands, so any standard SMA whip antenna will work. The cheapest price for these locally is around AU$90 each.
I offer spare antennas for $20 if desired. These antennas have been fantastic for my own on set work – I find they perform no better or worse than Remote Audio Miracle whip SMA antennas in my tests.
Where can the benefits of the mod be seen?
Film and TV sets are very demanding environments for radio receivers, due to wireless Teradek video transmitters, focus pullers, IFB’s, walkie talkies, wireless light controllers and other wireless radio microphones with intermodulation frequencies to compete with. On indie sets there is often a lot of poorly RF shielded and region non-specific cheap equipment being used in place of proper (and expensive) film standard equipment. In some specific situations, camera departments with faulty equipment can spit out very loud RF interference through a camera module’s SDI port. Even having the radio microphone’s antenna touch the body of the actor will greatly reduce transmission strength. (Pro tip, a child’s toy Nerf bullet with the tip cut off insulates from this very well!) In the above situations, an SMA modified radio microphone can perform 20-30% better, which sometimes makes all the difference on set.
Getting the most out of your radio microphone:
I recommend upgrading from a stock microphone to something like a Sennheiser MKE-2 EW Gold microphone. This upgrade will lower the noise floor, will be much easier to use without clothing rustling sounds and will squeeze some excellent sound quality out of these devices – they can often be found on eBay for $250 used (for an MKE-2 varient), or $350 new.
What I do:
I perform all of my Sennheiser SMA mods with an insulated solid hard wire internally for maximum bandwidth and to prevent the pin from being pushed inside the socket, this can happen if standard soft wire is used without any reinforcement. I also custom fit an SMA mount inside the chassis without glue, resulting in a mount that is pressure fit and well secured providing a solid grounding point for the antenna.
On Sony units I generally use a soft wire due to the high risk of tearing the flat solder pad off the motherboard and due to the routing within the chassis usually requiring a more flexible wire.
All of my SMA modifications are completely reversible with no original parts cut, modified or glued. All original parts and antennas are returned with each set.
On Sennheiser beltpacks, the 3.5mm locking ring surrounding the microphone/headphone jack is prone to twisting loose and backing out. On the transmitters, this ring acts as a grounding point for the metal top plate. If the ring comes loose the microphone’s sound output will cut in and out similar to a signal dropout. I add low strength Loctite 222 to the 3.5mm jack screw threads to prevent the ring from coming loose. If the locking ring has backed out and gone missing, I offer genuine Sennheiser replacements for $10ea.
After each SMA mod I perform a range test to see if the unit is performing up to my standards. Since the 3.5mm cable for the microphone or headphone can act as a diversity antenna (i.e. they will work without any antenna attached), my range test helps determine if the mod has been successful. However, it is difficult to definitively test the change in performance before and after the mod, especially with something as temperamental as UHF. UHF signal quality will vary greatly based on traffic, wind, wall reflectivity, nearby phones, time of day and even fluorescent lights.
Do I offer discounts?
I offer discounts to students or for bulk orders. Contact me and I’ll see what I can do.
Do I sell DIY kits?
Unfortunately, no. In the past I briefly offered DIY kits, but due to numerous issues with buyers not installing them correctly, and the time required of me to rectify these issues, I have stopped offering DIY kits.
I have repaired/re-modified some poorly modified equipment in the past. Poor repairs can potentially cause lasting damage to the device. One particular Sennheiser G3 modification had loosely fitted and poorly soldered the SMA mount into the chassis – the solder was not hot enough so did not weld properly to the mount. This resulted in loose lead solder rattling around inside the body of the transmitter. In this case I was able to repair it, but conductive metal bouncing around in an electronic device is not good for the device.
Do I perform microphone reterminations?
No. Lemac does them for around $50 each and they’re quite good, I’ve had them do some of mine. Just remember that Sennheiser and Rode 3.5mm jacks are wired differently to Sony.
What are illegal Frequencies?
If you own a particularly old Sennheiser G2/G3 or Sony UTX-B2/URX-P2 set with a particularly short antenna you might have an older frequency block that is no longer legal to use in Australia.
To summarise, in around 2014 the 700Mhz-800Mhz spectrum was reallocated into what is now digital TV stations and 4G wireless in Australia. This unfortunately means that Sony kits on channels 66-67 and Sennheisers on C or D band are operating on an illegal frequency in Australia. While they will continue to work, I would avoid using them, especially in any public place like at a sports arena with live TV broadcasting nearby.
Frequency legality is very region specific so you may be able to sell your equipment overseas. I can still repair and SMA modify this equipment which will improve the performance, but I would rather not take anyone’s money without them being aware of these restrictions first.
You can read more about illegal frequencies at the links below, or if you are outside Australia check your local radio frequency regulator.
https://www.acma.gov.au/what-spectrum
Can you change the frequency blocks of my equipment?
No. It is possible though it would require the manufacturer to rebuild the unit, I have come across one re-blocked transmitter before.
Can I increase the performance of my equipment for free?
On some Sony transmitters there's a high power option accessible in a hidden menu which definitely helps for range, basically instead of holding the POWER button to power it on, hold POWER and SET at the same time to power it on, then change RF POWER to HIGH and double tap SET to save it, then power it off and on again normally for it to function.
This will consume more power but will increase the range substantially.
Sennheiser G4 512's also have a similar option.
My Wisycom transmitters have a similar setting that I generally leave on, though the transmitters can overload the receiver when used in very close proximity.
Otherwise smarter techniques when micing up talent make a big difference, keeping the antenna away from skin contact and having direct line of sight with the receiver helps substantially.
Any tips to save money?
If your budget is particularly tight I'd recommend just SMA modifying your receivers to start with, particularly if they are a model with a single antenna like the Sennheiser range or if they are old, damaged or bent. Having a string antenna here makes a significant difference in reception quality and is how I used mine for the first 5 years or so, (as I didn't have flexible antennas back then)
SMA modifying the transmitters definitely brought an additional benefit and helped with signal stability more than anything, however not everything needs to be done at once.
Turnaround time:
Usually 1-2 weekdays for most orders. Turnaround time can be longer for large orders or if you have a new model that I am unfamiliar with. I run a pretty small operation which is just me working in my garage. I will let you know in advance if there are likely to be any delays. Let me know if you need the modification done quickly and I will see what I can do.
Location:
I am located in Hawthorn, Melbourne, Australia. Pickup and drop off to/from my house is free. Otherwise, I can take orders from Australia and New Zealand – postage is roughly $13-$19 Australia wide and $17-$30 to New Zealand each way depending on weight. Any additional insurance costs are up to you.
Shipping times are roughly 1-2 days from Sydney to Melbourne with Australia Post Express, roughly one week to New Zealand with Australia Post express.
When sending in your order I recommend Australia Post with tracking and strongly insist on Signature on Delivery.
I have never had an order not arrive or be stolen from my mailbox, but I do not want to take that risk. I cannot take responsibility for items lost in transit, so I strongly suggest tracking and Signature on Delivery.
I can do international orders, but postage costs might be prohibitively expensive. If you are from another country and are interested in my services, let me know.
https://auspost.com.au/parcels-mail/calculate-postage-delivery-times/
Packing your order:
I recommend including an additional postage paid return label inside your package so I can easily return it to you, otherwise make sure to include shipping costs in the amount you pay with the invoice.
Only one order has arrived damaged due to poor packing. While it was repairable, I recommend using plenty of bubble wrap inside a cardboard box with your items packed tightly to avoid things moving around inside. It also helps to prevent your items from touching each other with a layer of bubble wrap.
How to order:
All orders are custom and vary greatly, so send me an email, a text message or message me directly through Facebook Marketplace describing what you want and we can take it from there.