| Wireless for the Warrior - Volume 2 | Supplement No. 6 |
It has come to my notice that there appear to be some confusion on the use of some components, special issued items and aerial coupling methods for Wireless Set No.22. Many of the manuals and user handbooks are a bit vague on these subject (as is Volume No. 2 of 'Wireless for the Warrior'!!). This supplement, is intended to clear this matter.
Aerial 140-ft No. 1 on 12-ft masts is an 'All Wave' inverted L type horizontal wire aerial for Wireless Set No. 22, suitable for medium range communication (over 50 miles). Its advantage is that it can be used on any frequency within the coverage of Wireless Set No. 22 without making adjustments to its length. It was standard issue for special forces stations such as used by Airborne Signals. More can be found in 'Wireless for the Warrior', Volume 2, Section WS 22-16. The 140-ft aerial should not be confused with the series of 3/4 wavelength wire aerials as these had each a limited frequency range.
In order to match a 140-ft aerial to the Wireless Set No. 22, a special loading unit is required, 'Aerial Coupling Unit No. 4', a small box comprising two condensers and a switch. It is normally clipped on to the front grill of the set.
The aerial lead is connected to the top terminal of the Aerial Coupling Unit No. 4. A lug termination connects to the Wireless Set No. 22 aerial terminal and a 'bulldog' clip connects to a suitable earth point on the set, for example the metal handle. Depending on the frequency in use, condenser A (400pF) or condenser B (100pF) is switched in parallel to the set aerial and chassis. Note that Leads Counterpoise No.2 Mk.II must be used, normally arranged under the horizontal aerial.
Picture of Aerial Coupling Unit No. 4, clamped on the Wireless Set No. 22 grille. Three versions of this unit are noted: Mk.I (ZA 10560), Mk.II (ZA 22594) and Mk.IIT (ZA 27322), differing only in small detail.
Totally different in use to the arrangement above is the Wireless Set No. 22 'Remote Coupling Equipment J' which enables a rod aerial or suitable wire aerial to be used at a distance of up to 50-ft from the set. See the Gallery section for a description.
You may have asked yourself: '..what does 'X5' stands for .. and what is the actual value of this condenser
which can be found in many vehicle installations from the 1940s up to the late 1950s..'
This small table should give a clue how this worked.
Apparently this classification was devised well before WWII, it was abandoned early in the war,
but somehow several aspects remained in general use.
| VOAS nomenclature for condensers | |
| P | x100.000pF |
| Q | x10.000pF |
| R | x1000pF |
| X | x100pF |
| Y | x10pF |
| Z | x1pF |
END