[Premium-Rx] Hiya fellas -- good to meet you!

[ToddRoberts2001 at aol.com]

Hi Craig, welcome to the list from a fellow NDB beacon DX enthusiast and also 
an owner of a Mackay 3031A Rx. There is a way to add LSB to a 3031A without 
having to change or modify any of the crystal I.F. filters in the set. When you 
switch the receiver to the CW variable mode you will notice that CW is 
received in USB mode also but that you can swing the variable BFO almost to zero 
beat. I will have to look back in my notes but there is a fairly easy way to 
either add inductance or capacitance to the variable BFO circuit to allow swinging 
the BFO past zero beat and over to the other side for proper LSB reception. 
The BFO is tuned using varactors so I believe adding inductance to the circuit 
will swing the BFO to the other side. This enables proper LSB reception when 
the BFO is placed in the variable CW mode. USB mode uses a fixed bandpass I.F. 
crystal filter of approx. 2.4 KHz bandwidth. When In the CW mode you have a 
choice of 4 filters. By using the 2KHz filter in CW mode  you will closely 
approach the same bandwidth of the USB filter. The frequency readout will be 
affected when listening to LSB in the CW mode but if you choose to offset the BFO 
about 1KHZ then you can mentally add or subtract 1KHz to the readout which makes 
tuning LSB a little easier. The added inductance can always be easily removed 
if you want to return the receiver to the stock configuration. If someone 
wanted to get really fancy they could have a custom LSB crystal filter made up 
and install it in the RTTY slot and use that for LSB mode but that would be a 
much more expensive and involved project. 73 Todd WD4NGG.


Good evening Gentlemen,

I'm a new member to the list, having just acquired a nice Mackay Marine 
3031A -- a receiver I've wanted since they were introduced many years ago.

I'm also an active amateur radio operator (a boatanchor fan) and plan to 
build a Class E solid state transmitter as a companion to my "Premium 
RX" soon.

Oh yes -- I'm also a beacon enthusiast, after a fashion. I've been a CFI 
(Certificated Flight Instructor) for over 35 years and have taught 
hundreds of students the fine, if nearly lost, art of flying an NDB 
approach. Until I began monitoring this list I had no idea people 
actually listened to these little transmitters for fun. Who'da thunk?

I do have a technical question. Has anyone added LSB capability to the 
3031(A)?

Many thanks and 73,

Craig Roberts
W3CRR
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.qth.net/pipermail/premium-rx/attachments/20050412/c091f899/attachment.htm