Re: X-10 RF meter (was Re: XTB II Review)

[Marc_F_Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Thu, 04 Jan 2007 20:08:45 GMT, "Jeff Volp" <JeffVolp@xxxxxxx> wrote in
message  <h9dnh.641964$QZ1.33798@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>:

>"Marc_F_Hult" <MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote in message
>news:ghfqp257tr59qhe472qjbdenvksr4tkouj@xxxxxxxxxx
>
>> So a one-off X-10 RF signal strength sniffer/meter could indeed be
>> constructed *without* programming for ~$15 or so (depending in part on
>>what  is already in your electronic junk box).
>
>While I agree a DIY version without a custom PCB or case can be put
>together cheaply, I don't know of any electronic distributers that offer
>free shipping.  That can become a significant factor when buying from
>multiple sources.

Yep ;-)  IIRC both Mouser and Digikey offer inexpensive shipping at USPS
postage cost if you meet the minimum (which is yet another gotcha unless
you have the patience to combine requirements/orders). Arrival to Greater
Cincinnati is 2-3 days. A light package with a few chips (assuming that
they don't overpack ! ) might cost $2-3.

What bumps up my purchase cost as much or more than shipping costs is my
inclination to buy multiples of components. Who wants to get into a late
night session only to wonder whether the problem is a particular IC and not
have a spare to substitute? I'm usually too impatient to wait days for a
replacement/substitute  and so a single component that costs X$ often ends
up costing me 2X$ (or more).

So as a practical matter, the first one of most/many things costs
significantly more -- depending on home much is in my junk box/room. I
could for example (depending on what RF receivers I find)  build the first
few of these sniffer/meters with what I already have. I know I have the
LM391xs and all the other components.

But $15 is about the price of one CD. Does it really matter if you save the
cost of golf fees (or whatever you call them -- I don't golf) by spending
the equivalent of one or two CD's on a less expensive hobby?

... Marc
Marc_F_Hult
www.ECOntrol.org




>I had used a receiver some time ago that included an analog RSSI output
>(received signal strength indicator).  That was useful to determine how to
>dynamically configure the RF network for best performance.  The RSSI
output
>could be monitored by a VOM.  However, because of the pulsed nature of X10
>signals, some type of filter or peak detector may still be needed.
>
>Jeff
>