[Milsurplus] Australian WSA-38

[Robert Nickels]

On 5/4/2018 1:31 PM, Hubert Miller wrote:
> the VFO frequency changed for transmit to 1/2 the output frequency.
>
Actually the VFO is doubled in the Mk I and II versions for both 
transmit and receive mode.   Apparently they were able to achieve the 
needed stability without doubling in the Mk II* and the values were changed.

Based on the Training Notes, there were three versions:  "In the case of 
Mk I and II sets the grid circuit of V1B oscillates at half the output 
frequency i.e. (S+I.F) but in MK II* sets the values of the components 
in the compensating network are such that oscillations are produced at 
the output frequency".   The MK II* configuration is shown in Fig. IV 
but the only coil value given is the 16uH indicated on the schematic for 
the Mk I and II versions .

The alignment procedure is to first set the endpoints of the VFO in 
transmit mode, then adjust the coil and trimmer that are switched in on 
receive for proper tracking.   They say the tracking error between TX 
and RX should not exceed 3 kHz after alignment, which is certainly good 
enough for a QRP radio with broad selectivity.

Thanks for posting the links to this most intriguing radio, Ray.

73, Bob W9RAN