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-   -   Wireless UHF or VHF (https://www.dvinfo.net/forum/all-things-audio/47022-wireless-uhf-vhf.html)

Darrin McMillan June 30th, 2005 11:29 AM

Wireless UHF or VHF
 
HI There,
I'm looking to pickup a wireless receiver and 2 transmitters. I'm on an extreme budget and can only go as high as 400 Canadian. I'm concerned more about interference then quality. I can fix some of the quality issues in post, however interference would be a major problem. What is better VHF or UHF? Does anyone know of a solution that might work for me? Thanks in advance.
Darrin

Lauren Mey July 14th, 2005 04:55 PM

I don't know much about audio - but in a recent trip to B&H I asked for an explanation of uhf vs vhf and I was told you want UHF. VHF is very crowded and you may have problems finding a usuable frequency. I would guess that if you were not in a city your chances of being able to use VHF might be a little better - but I have had problems getting decent audio trying to use VHF wireless lavs. Thankfully, I have had professional sound people to troubleshoot this and use their UHF transmitters/receivers.

Doug Fearman July 14th, 2005 05:19 PM

Hi Darrin,
I've shot 4 weddings in (relatively) rural settings using an azden pro vhf wireless lav mic ($135 at b&h) and have had no problems.
If however you can afford UHF; go for it.
doug

Douglas Spotted Eagle July 14th, 2005 07:35 PM

Quote:

Originally Posted by Doug Fearman
Hi Darrin,
I've shot 4 weddings in (relatively) rural settings using an azden pro vhf wireless lav mic ($135 at b&h) and have had no problems.
If however you can afford UHF; go for it.
doug

The "rural" is likely why you're getting away with it, additionally if you're close.
VHF (very high frequency) operates in more or less the same bandwidth as your FM radio and toy band (remote control cars)
UHF is substantially higher, in the upper television band.

From my recent book on field production of audio:

VHF systems are basically the same thing as FM radio. In fact, some of the least expensive systems actually allow or force you to use an FM receiver from a home stereo or something similar. VHF wireless systems also use the same frequency bands as the upper bands of analog television. VHF operates typically in the range of 169.5 - 213.8 MHz (Megahertz) The biggest challenge with VHF is the long wavelength. Longer wavelengths mean that there is greater opportunity for interference. This is where UHF comes in.

Ultra High Frequency (UHF) systems are higher in frequency bandwidth, which means their wavelengths are shorter and therefore are less open to interference. UHF systems also carry a higher cost. However, if you’re in a run n’ gun production, or if the production team is moving from city to city, or even from one area to another area in the same city, UHF is the best option when wireless is required.
UHF systems also operate in the same frequency bandwidth as television, in about the same area as channels 38 through 70, or in the range of 650.1 - 806 MHz (Megahertz) Up until recently, this has been great for users of wireless systems. However, with the advent digital television, you’ll need to exercise greater diligence in checking out your signal before a shoot. DTV doesn’t allow as much free space in the bandwidth that analog television has offered us in the past. While the FCC has recently made allowances for this by opening up the 2.4 Gigahertz range for wireless mic systems, these are very expensive and not easily accessed. Further wireless home telephones, microwaves and other devices also function in this frequency range.
Be sure that the UHF system has easily switchable channels. Both the receiver and the transmitter need to be able to change channels, and quickly. Audio Technica and other manufacturers provide a small screwdriver inside their transmitters, with knobs on the front of the receiver, allowing very fast channel changing. If you’re doing a lot of wireless work and traveling from city to city, consider software that scans the area and provides a readout of what channels are available.


UHF on the lower side costs about the same as VHF in the higher quality side.
Factors in your choice should be:
1. Environment you'll mostly be in. (don't consider VHF in big city downtown like NYC)
2. Distances you'll be working
3. Amount of control/time you'll generally have for set up

Most higher quality wireless' today sound pretty good. Question is more about their flexibility, cost, and your needs. Flexible is more expensive, but if you're in an urban environment...you'll likely want it.

Doug Fearman July 15th, 2005 03:29 AM

Hi Douglas,
Thank you for sharing your knowledge. As an amatuer videographer I appreciate all the helpful information that is shared on this forum. I was told by a person at b&h that I should go with UHF but for videotaping family and friends weddings my $135 VHF system has worked well. (Because of the rural location and the 15-20 feet distance between the transmitter and receiver.) If I should decide to charge for my services I'll be buying a UHF system. All the best with your book Douglas.
doug


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