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Title: Looking for a schematic - Admiral 399-6M desktop radio Post by: ka1tdq on October 12, 2013, 09:22:51 AM I came across yesterday a WORKING Admiral 399-6M desktop radio. It covers the AM broadcast band and 1.6 to 4.0 MHz shortwave. I want to tighten the shortwave band VFO to 75 meters AM voice, but can't find a schematic for it. I think the radio was built around 1939 according to what information I've found on a few websites.
I was planning on using a SoftRock Ensemble II for my 75 meter receiver, but I haven't gotten the nerve yet to start the boring process of kit building. I found this radio at a Good will store so I might go with that for the time being. Jon KA1TDQ Title: Re: Looking for a schematic - Admiral 399-6M desktop radio Post by: ka1tdq on October 12, 2013, 02:31:13 PM Actually, it looks pretty simple. I will just change the antenna tank circuit going into the detector tube 12SK7 and narrow the response down to around 3.50 to 4.00 MHz. The existing VFO capacitor looks to be around 250pf max for one gang. I'll put a series limiting fixed capacitor in to limit bandwidth. Then I'll just throw on 5 turns around the coil for a primary tap for the coax.
...not my ideas, but just borrowing them from the AMwindow.org Jon Title: Re: Looking for a schematic - Admiral 399-6M desktop radio Post by: Joe Connor on October 12, 2013, 08:59:41 PM Jon:
This may be your schematic: http://www.nostalgiaair.org/PagesByModel/013/M0003013.pdf Note that there are schematics for several different models on these two pages so check the one for the 6M and see if the parts layout and tube layout match yours. Joe Connor Title: Re: Looking for a schematic - Admiral 399-6M desktop radio Post by: W7TFO on October 12, 2013, 10:53:06 PM Lotsa' good folk here, too: AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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