Block 22 contains frequencies usuitable for the Sydney area. This is not an opinion, but a statement of fact.
The spectrum between 561-603 MHz is adversely affected, to varying degrees, throughout Sydney and environs. The table below shows those transmissions impacting upon Block 22.
Area | Licensee | Channel | Freq | Transmitter Location |
| Sydney | Digital 9 | UHF 33 | 561 - 568 MHz. | Translator North Head |
| Sydney | Digital 9 | UHF 33 | 561 - 568 MHz. | Translator Kings Cross |
| Gosford | Digital SBS | UHF 34 | 568 - 575 MHz. | Bouddi / Broken Bay (Alt) |
| Gosford | Digital SBS | UHF 34 | 568 - 575 MHz. | Wyrrabalong Wyong (Alt) |
| Sydney | Digital SBS | UHF 34 | 568 - 575 MHz. | Main Transmitter Gore Hill |
| Sydney | Digital SBS | UHF 34 | 568 - 575 MHz. | Translator Kings Cross |
| Sydney | Digital SBS | UHF 34 | 568 - 575 MHz. | Translator North Head |
| Sydney | Broadcast Australia | UHF 35 | 575 - 582 MHz. | Gore Hill |
| Wollongong | Digital WIN | UHF 36 | 582 - 589MHz. | Knights Hill (Kiama) |
Although Kiama seems far away, the power (effectively half a million watts) is concentrated north into Wollongong. Reports of inference in Sydney’s southern suburbs and oceanfront areas are common, along with any high locations. SBS transmits 200,000 watts from Gore Hill and can create interference almost anywhere in Sydney. The Kings Cross translators can wreak havoc within Fox Studios at Moore Park despite their comparatively low-power of 1kW.
Interference can appear as extraneous buzzing noises, squelching (muting) and, in particular, loss of range. Digital TV interference ranges from mild, to very severe, depending upon geographic location and elevation.
Q Is it possible to change from Block 22 to interference-free frequencies?
If you have one of the older crystal-locked systems (190/195 models) – yes.
If you have an IFB, or one of the 200/201/205/210/211 systems, probably not.
Contact your equipment supplier.
Q Can I just ignore it?
Yes, but only if you are prepared to accept severely reduced range in some areas. If you only do ‘pieces to camera’ over five metres, you might escape unscathed.
Q How can I tell how bad the inference is?
With your transmitter switched off, set the RX metering to RF and check how many LEDs are on. Some later model receivers have a spectrum analyser display to help you to find a ‘quiet spot’.
Q Are there any other options?
Yes. If you have two systems or less on Block 22, set their frequencies to 568.000 (Hex 30) , or 575.000 (Hex 76), or 582.000 (Hex BC). If you attempt to use all three channels simultaneously, you will introduce an intermod problem that may negate any gains.
The interference on those three channels is very significantly lower and will improve performance. Any frequency above 582.000 is generally better than those below 582.000 - except when you are in Sydney's southern suburbs.