[AMRadio] AM from a HW-101

[Jim Isbell]

I find the 75S-1 to be an excelent receiver on AM/CW/SSB without any 
modification.  I wouldnt do anything to mine for fear of screwing up one 
of the best designed receivers in the world.

I might try to get AM out of the 32S-1 however.  There is a mod for that 
on the 32S-3 and I am sure it could be adapted to the 32S-1

Brett Gazdzinski wrote:

>The resale value aside, I think the 32s-1 would do better,
>I think it actually uses a 455khz IF, you might be able to do something
>with that.
>The 75s-1 type receiver could likely make a real nice AM receiver, top
>quality,
>with the addition of a good kiwa filter in line with the back to back
>IF transformers used on AM.
>Standard setup is way to wide, but a 5.5khz filter between the transformers
>(tacked on) would do wonders.
>it would only be in circuit when the AM mode is selected.
>It could be tacked on without any modifications, and you
>could power it from rectified filament voltage, or even batteries.
>
>Some slight circuit changes and an external audio amp, and you have a great
>overall receiver for cw, ssb and AM.
>
>Any rig that runs 100 watts pep output on ssb is only going to be good for
>10 to 20 watts of AM, but driving an amp would be useful indeed.
>
>Its easy to unbalance the modulator using a small pot
>(for carrier level control), getting both sidebands I would have to
>look at the design....
>
>It would be quite neat to have a nice sounding well working
>Collins S line on AM and ssb.
>
>Perhaps trade the hw101 for a less nice 32s-1 and try experimenting on that.
>
>What about screen modulation of the amp?
>That would likely get you a few hundred watts of AM out, with very little
>audio power.
>Modulation can be very nice if kept on the low side, don't expect 150%
>positive, but I have heard some really nice DX60b transmitters
>running screen modulation...very good fidelity overall.
>
>If space is at a premium, take over the basement, put a couple of small
>rack cabinets on the desk, one big 6 foot rack in the shack, a
>shelf above the S line, or get something like a Gonset G76.
>The G76 runs about 70 watts of plate modulated AM output in a unit
>smaller than a 75s-1, and its a trans-receiver.
>The receiver uses a 262Khz IF, which works well, its quite attractive,
>stable, accurate, and fun to operate.
>It does 80 through 6 meters, AM and cw, and can copy ssb.
>
>Its got problems, audio quality is not top notch, but they are
>extremely robust radios.
>I operate mine at higher voltages then you are supposed to, its been
>abused at pre hamfest drunken campouts, complete with rain, excessive
>beer, wires thrown up in trees, and it just always works.
>
>I used to have two of them, but sold one for some reason.
>
>They seem quite rare these days, I don't know why.
>Its smaller than a ranger, puts out more power, and has a good receiver
>built in.
>
>I made some changes to mine, removing the receiver audio output section
>that used the transmitter audio driver tube and transformer, and installed
>a small IC chip that does 6 watts of hi fi audio.
>Lots of feedback around the modulator cleaned things up nicely,
>low frequencies do not pass the driver and mod transformer well,
>the driver transformer could likely be improved, but there is no room
>for a bigger mod transformer if you want it inside the nice slide
>off case.
>I might look into something like a pair of AB1 tubes as modulators
>instead of the triode connected 6DQ6 tubes.
>Crazy setup, triode connected, the suppressor grid gets the audio
>signal input I think!
>
>They are easy and fun to work on, two screws and the case slides off.
>It weighs about 10 pounds, easy to toss about.
>
>Did I mention its FUN to operate, and quite attractive with its backlit
>tuning dial and meter?
>
>Takes a D104, an antenna, and away you go.
>Anything will work as an antenna, even a wet noodle, nothing
>seems to bother the rig.
>Its got a low power mode (10 watts) and a high power mode,
>depending on how much you load it, 70 to 90 watts out.
>
>If I could only have one very small radio, the G76 would be it.
>
>Brett
>N2DTS
>
>
>  
>
>>-----Original Message-----
>>From: amradio-admin at mailman.qth.net
>>[mailto:amradio-admin at mailman.qth.net]On Behalf Of Jim Isbell
>>Sent: Thursday, December 11, 2003 10:02 AM
>>To: amradio at mailman.qth.net
>>Subject: Re: [AMRadio] AM from a HW-101
>>
>>
>>Brett Gazdzinski wrote:
>>
>>    
>>
>>>Why would you want to do that?
>>>
>>>
>>>      
>>>
>>Well, to answer your question,....because there is not more
>>room on my
>>desk for ANOTHER piece of equipment.  I already have a 32S-1, 75S-1,
>>Station Console, and Power supply for the full S-Line, a
>>4-1000A Linear
>>amp, a computer and now the HW-101, .  There is no more room.
>> If I want
>>AM it has to be from the 32S-1 (wonder why the 75S-1 has AM
>>but the TX
>>doesn't??) or from the HW-101.  But then I could plate modulate the
>>4-1000A with a pair of 833As in push pull...but I think that would
>>really take up some room, and the winters are not cold enough
>>for that
>>down here on the Third Coast.
>>
>>I have a Viking Ranger, but no room on the desk for it.
>>
>>
>>
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