Quick, and easily answerable question

UHF
or
VHF

which is best.... ?

UHF

Jimbo

UHF,


have you not noticed they cost more

whats the difference? (apart from price)

matt

One is Very High Frequency
the other
Ultra High Frequency

Anne

UHF

UHF has a better radio signal, you need less transmitting power and smaller antennae, you are less likely to suffer drop outs and interference. There are more license-free channels available for simultaneous compatible use. VHF are beginning to be regarded as old-fashioned by professional users.

erm UHF

Just to cast a technical spanner in the works, is not VHF less affected by solid obstructions? (Walls, large women etc)
Well, my knowledge of radio tells me this is the case in theory.

Suppose it doesn't matter so much with diversity systems.....

My understanding is VHF transmits over a long distance ie. - ship to shore.
UHF has a better quality sound due to the radio waves being very close together.
So if you want to use your mics for school sports days or the local town gala which is going to cover a large area maybe VHF should be the one for you.
If your a pro singer on a stage with nothing to obstruct the device go for UHF. As Andy just pointed out a wall can cause loss of sound.

Anne

Simply

Technically, yes, the higher the frequency the more it is likely to be blocked by structure. It is also more likely to be reflected rather than absorbed as the wave length is shorter. Hence the use of satellite dishes that 'focus' the waves into the LNB (receiver+converter).

You are less likely to get interference from other users as the range is limited due to blocking by walls etc .

Higher frequencies generally means better construction as the technical requirements to maintain a stable frequency are greater. Hence the usually higher price of UHF mics.

Generally it is line of sight communication. I regularly use similar power levels used in radio mics to communicate with other radio amateurs many thousands of miles away (Canada Japan etc) via satellites 100's of miles above the earth. This does use advanced antenna systems but demonstartes clearly the line of sight princible. If you have a clear path your signal levels will be higher. Lots of radio mic issues can be solved by just getting the mic receiver as high as is practically possible and away from flight cases etc.

Also the power levels are limited to fractions of a watt (milliwatts) so when someone walks between the mic and receiver the path loss(signal) is very high (in excess of 20db or more (100 times less) so the singer/MC may also block the signal with their bodies. Generally when ranges are quoted it is for a CLEAR LINE OF SIGHT PATH. When a range 50m or more is quoted (unless you are paying in excess of £1000 when advanced technology is used) you can expect it to be less in real life use. Roughly half the distance quoted would be reliable.

You can also get interference from other electrical and electronic devices.
Power supplies. Baby alarms. mobile phones and mains bourne interference. VHF is more prone to this type mainly because there is more of it!

Generally you get what you pay for.

Jimbo

Well put Jimbo.

VHF is seldom used in professional circles, eg stage/studio/tv. These 'professional' users will only consider UHF.