[Orion] Orion subreceiver AM detector

[James C. Garland]

Hi Gang,
I'm a newbie to this reflector, so pse forgive me if I'm treading over old 
ground.  A question about the Orion's AM detector:  When listening to AM 
stations,  I notice that the subreceiver seemz  to lock in on AM stations, 
in the same way that FM radios with AFC lock in on stations. In other 
words, when slowly tuning across an AM station, the station will suddenly 
snap into audibility.  Even a  1 Hz change in frequncy cam cause this to 
happen. I haven't noticed this effect when tuning AM on the main RX, though 
I haven't investigated it thoroughly. Is it possible the Orion is using a 
synchronous detector on AM for the subRX, which is what this sounds 
like?  When tuning across an AM broadcast band, I hear a popping noise as 
each station pops in and out of range. I find this a bit disconcerting.

A few other quibbles: (1)  the volume encoders work with a linear rather an 
audio taper. Thus a 180 degree rotation of the AF gain causes practically 
no change in volume, whereas the second 180 degree change increases the 
gain very rapidly.  I hope that in a future SW revision, the audio controls 
are given an audio taper, so they will have the "feel" of a true volume 
control.

(2) When using the mute buttons, rotating the volume encoders toggles the 
RX out of the mute mode. This is a convenient feature, except that it only 
takes a microscopic rotation to unmute the radio. It's not easy to push the 
button without slightly turning the encoder, which often gives the 
impression that the mute button isn't working right. I hope it's clear what 
I'm talking about. Decreasing the sensitivity of the rotation unmute 
feature would be desirable.

(3) The tuning step selections are not optimal, in my opinion. 10 Hz is too 
slow and 100 Hz is too fast. A 50 Hz step would be very desirable. Better 
still would be a user-defined step size. My Watkins-Johnson HF-1000 had 
this feature and it was very nice.

(4) The synthesizer seems to lock slowly, making rapid frequency excursions 
sound jerky. The Collins KWM-380 behaves this way, but then it is a 25 year 
old design. Most other modern rigs have fast enough synthesizers that the 
tuning seems analog. Too bad the Orion can't do this as well.

Some of these criticisms may be a consequence of my unfamiliarity with the 
radio, which I've just had for a day. If so, pse excuse me.
73,
Jim  Garland W8ZR