[Radio Wrangler]

It's the borderland.

Sets which try to do somewhat more than is needed for a domestic broadcast entertainment receiver, but don't go as far as high performance mode-specific filters for Dingle Sideband, Morse and data modes. You could use them for shortwave broadcast and some of themhave multiple or variable bandwidth for AM speech and maybe Morse.

The AR88 and HRO mentioned have switched bandwidths making them OK for AM music, AM speech and can bring in a quartz crystal to make them quite decently narrow morse receivers. They pre-date the adoption of other modes.

So there is a fair old mixture of vintage receivers out there. Sets for government/military, sets for spooks, sets for radio amateurs, sets for maritime use, sets for aviation ground stations, sets for shortwave listeners, and then all the domestic broadcast jobs.

Preferred modes and roles moved around a lot over the years.

If you wanted to categorise them, you'd need a two-dimensional matrix to spread them out by what and by when.

Some broadcast receivers of the posh sort sported variable bandwidth so you could bask in the audio quality of a locak station in 'wide' or go narrow to winkle out something distant.

I have a couple of Racal receivers with switched banks of mode-specific filters for CW, SSB two bandwidths of AM and also filters for teleprinter modes.

My AR88 has five bandwidthe, two by switching coil coupling, and three with a quartz crystal added to make it sharp for separating Morse signals.

My Eddystone EA12 moves coils in IFTs to vary coupling to do AM and to make a fairly poor go of SSB. A crystal comes in for morse. THis set is right from the beginning of SSB on the amateur bands in the UK and is a half-way step towards getting it right.

To complete the variants, My Icom 7700 mixes everything to switched crystal filters near 60MHz, then mixes down, digitises and does all the real selectivity in DSP. With this I can play with bandwidths, offsets, slopes and notches all at once with shapes for all the current modes. Gross overkill? Yup. Works a treat, but not vintage for many years to come.

David