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Title: NC-300/303 Mounting ? Post by: WA2ONK on September 17, 2008, 10:19:43 PM I've never seen one "up close and personal", can the 300/303 be rack mounted?
I have some room in the rack...... Chuck.. Title: Re: NC-300/303 Mounting ? Post by: Steve - WB3HUZ on September 17, 2008, 10:27:54 PM The 303 can and I'm pretty the the 300 is the same.
Title: Re: NC-300/303 Mounting ? Post by: Pete, WA2CWA on September 18, 2008, 12:26:28 AM You could also use a rack shelf.
Something like this: http://www.racksolutions.com/rack-shelf.shtml Saves having to store a cabinet somewhere unless you don't have a cabinet for it. Title: Re: NC-300/303 Mounting ? Post by: W1ATR on September 18, 2008, 09:04:42 AM Yup, they are both the same chassis.
Title: Re: NC-300/303 Mounting ? Post by: KB5MD on September 18, 2008, 01:27:39 PM While we're on the subject, what is the difference between an NC 300 and a 303, other than the extra knob on the front?
Title: Re: NC-300/303 Mounting ? Post by: WBear2GCR on September 18, 2008, 03:45:18 PM ...ummm? maybe... Three? ;) _-_-bear (sorry couldn't resist the temptation...) Title: Re: NC-300/303 Mounting ? Post by: Pete, WA2CWA on September 18, 2008, 03:58:31 PM While we're on the subject, what is the difference between an NC 300 and a 303, other than the extra knob on the front? The "Dream Receiver" (NC-300) probably was conceived during a bad nightmare. National issued a number of service bulletins during its life cycle. Over the years, I've had 3 NC-300's and none of them agreed completely with the schematics that came from the factory. Second try, "Dream Receiver" (NC-303), some additional features and the design was far more stable and not subject to numerous changes. NC-300 Complete Specs (http://www.io.com/~nielw/nat_list/nc300.htm) NC-303 Complete Specs (http://www.io.com/~nielw/nat_list/nc303.htm) Title: Re: NC-300/303 Mounting ? Post by: Steve - WB3HUZ on September 18, 2008, 05:47:06 PM The biggest difference in front panel function are selectable upper and lower sideband filters and a better product detector for SSB.
Title: Re: NC-300/303 Mounting ? Post by: WA2ONK on September 18, 2008, 06:44:45 PM Thanks......
Title: Re: NC-300/303 Mounting ? Post by: W1ATR on September 18, 2008, 10:42:50 PM Bear, lemmee help ya out.
They're in the bathroom, in the medicine chest on the second shelf to the right.... Take two, with food.. ::) ::) Title: Re: NC-300/303 Mounting ? Post by: John K5PRO on September 19, 2008, 12:54:41 PM The NC300/303 have a wierd way of mounting the receiver into the cabinet. Instead of having flat rails that are tapped with threaded holes, on the sides, and using rack screws (like standard #12), they have threaded studs sticking out front, and a trim strip covers this. Nuts are applied on the front panel to the threaded studs. Backwards from any radio I've seen.
See them here: http://www.virhistory.com/ham/nc300/nc300.jpg Nick, KD4CPL, has a nice site on these RX. Title: Re: NC-300/303 Mounting ? Post by: KM1H on September 29, 2008, 08:19:43 PM In addition to the above: AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
The NC-300 uses a free running oscillator for the 2nd conversion and the 303 is crystal controlled. Any 300 that came thru the National Service Dept had the crystal conversion done at no charge. That alone contributes to the majority of the stability improvement. SSB reception is marginal even with the 303 mainly due to the 6BE6 PD/BFO. The audio output is loaded with distortion products and the tube itself is extremely noisy. A 6BY6 is a bit better but a dual triode ( consider a 6J6 in a Pullen) would be a huge improvement as a PD with a seperate BFO. Carl KM1H National Radio 1963-69 |