Ch 2 VHF DX TV; possible in 2013 ?
With the introduction of Digital TV broadcasting in Australia;
Perth W.A. Analogue service will discontinue on 16 April 2013.
However the Melbourne Vic' transmission remains in service until planned termination on 10th Dec 2013.
Therfore with an "open" Ch 2 frequency allocation, and a good receiving set-up; it may be possible to receive East-West low-band VHF ABC TV during the April-December 2013 "window"
One would also hope that sunspot cycle #24 (which so far has been very dissapointing) would enhance propagation.
The graphic shows Adelaide TV received in Perth in 1960 - soon after a sunspot cycle peak ('57).
I presume the Gamma-Match gets its name from the similarity of the tuning bar and tap-off point,
to the Greek capital letter gamma ( Γ )
References:-
1) VHF Handbook for Radio Amateurs.Herb Brier W9EGQ & William Orr W6SAI 1984 pg 241
2) The Radio Handbook 14th Ed. Editors and Engineers (William Orr) 1956 pg 429
E&E gives capacitor value as 7pF per metre of wavelength (λ)
With the introduction of Digital TV broadcasting in Australia;
Perth W.A. Analogue service will discontinue on 16 April 2013.
However the Melbourne Vic' transmission remains in service until planned termination on 10th Dec 2013.
Therfore with an "open" Ch 2 frequency allocation, and a good receiving set-up; it may be possible to receive East-West low-band VHF ABC TV during the April-December 2013 "window"
One would also hope that sunspot cycle #24 (which so far has been very dissapointing) would enhance propagation.
The graphic shows Adelaide TV received in Perth in 1960 - soon after a sunspot cycle peak ('57).
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This is a yagi antenna which I "scaled" from
70MHz to 64.25MHz
using a design of Martin - DK7ZB (version 2)
For construction: I recycle, dismantled Australian Hills brand domestic TV aerials.
using a design of Martin - DK7ZB (version 2)
For construction: I recycle, dismantled Australian Hills brand domestic TV aerials.
| 64.25 MHz | Element-position | Element-length (10 mm dia) |
|---|---|---|
| Reflector | 0 mm | 2332 mm |
| Radiator | 858 mm | 2306 mm |
| Director 1 | 1164 mm | 2142 mm |
| Director 2 | 2153 mm | 1989 mm |
GAMMA MATCH ( Γ )
I presume the Gamma-Match gets its name from the similarity of the tuning bar and tap-off point,
to the Greek capital letter gamma ( Γ )
References:-
1) VHF Handbook for Radio Amateurs.Herb Brier W9EGQ & William Orr W6SAI 1984 pg 241
2) The Radio Handbook 14th Ed. Editors and Engineers (William Orr) 1956 pg 429
| A (pF) | B (cm) | C (cm) | |||||
|---|---|---|---|---|---|---|---|
| Frequency {MHz} | Wavelength (m) | E&E | Orr | E&E 10% |
Orr 14% |
E&E 1.43% |
Orr 2% |
| 64.25 | 4.7 | 33 | 50 | 23 | 32 | 3.2 | 4.6 |
| Average | 42 | 28 | 3.9 | ||||
E&E gives capacitor value as 7pF per metre of wavelength (λ)
| Uncritical broadband
design, great bandwidth
This Yagi is a scaled version of the well proved Lightweight-2-m-Yagi |