29937Re: [midatlanticretro] Re: Altair / Fool on the Hill question
- Mar 29, 2013On 03/29/2013 11:46 AM, joshbensadon wrote:
>>> right inside the Altair. Start the demo by lifting the lid ofFerrite
>> Also, remember distance is your friend. unless there are
>> directional antennas involved, signal strength is inversely
>> proportional to the square of the distance.
> Yes, I had that in mind too when I suggested putting the radio right
> inside the Altair box! Part of the demo is to show how it was done
> wirelessly, but given the circumstances, it might need to go inside
> the box. Also, he will need to watch that an open Altair box doesn't
> interfere with his neighbor's demo.
> But, things might just work outside of the box, if the radio is
> placed at the right position/angle.
> I wish I had more experience with the Altair Radio Music. But I know
> the AM Radio antenna is based on a ferret stick,
> which should be directional.Ferrite "loopstick" antennas are very broadly directional. They have
nulls off the ends but they're not terribly deep.
> But, I think the interference really happens at the IFActually I'd be kinda surprised if the interference in question
> stage, which is further down the receiver circuitry. If that is
> true, you could remove the ferret stick antenna.
happened at IF. Those IFs are typically 455KHz; you're much more likely
to get interference from higher frequencies than that in ~1~8MHz
I've done it with a PDP-8; that interference comes from the
high-current pulses in the core memory subsystem if memory serves. The
interference there isn't at IF.
> I'm sure the demo will sound good enough to get the point across. II think it'll be great!
> just like the idea of opening the Altair Lid to show off the
Dave McGuire, AK4HZ
New Kensington, PA
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