Hello All,
Hello All,
So, am I to understand that LPAM is useless at night. I notice empty stations during daytime but at night these same stations are filled with all kinds of junk. Is the LPAM signal just to low to complete with these more robust stations? Does anyone have any success at night or do you just shut it down until daybreak?
as a general rule part 15 am is useless at night. carrier current (15.221) has a chance of overcoming night time interference without risking causing night time interference but part 15.219 is almost always totally and completely useless at night. in very very rare instances 1700 khz will be free and clear of night time skywave but thats it.
There are many variables that come into play on AM after dark.
The ideal night situation would be to have a frequency that was as empty as possible of either distant or skywave signals.
In fact, on a very clear channel, your station might be heard very well at some distance.
Some listeners in your area might have different reception than you do. For me, down in a bowl, surrounded on all sides by hills, there is less reception of far away stations at night than neighbors up on top of the hills, who are spray-painted with radio energy.
In any case, the best LPAM distance is experienced at mid-day.
If I were considering having my transmitter solar powered, it would behoove me to forgo a battery so as to broadcast at night?
A midway solution I suggest is to install the smallest storage battery so you can run nighttime tests to observe your results.
If nothing else, this could be an interesting experiment.
In our nightime service, reception here indoors is strong all the time, for our own listening.
you would still need a battery for days you don't have enough sunlight. the system can be remote controlled to turn off at night.
Also of note is the different behavior of radio waves in different seasons.
Winter weather has long been regarded as the DXer's best season on AM and shortwave for hearing robust long distance radio reception. Therefore part 15 AM is at a greater disadvantage in the long winter nights.
Summer not only provides more daylight hours, but the nighttime activity is far less and might be a good time for the part 15er.
"you would still need a battery for days you don't have enough sunlight."
For those times a wind driven generator comes in handy. Be really creative and take a yard wind mill and mount a generator to that turbine and feed to a regulation and switch over circuit and there you go.
Besides, even if just running solar panels, you want to run that voltage through a regulation and some kind of steering circuit so as to not over-charge the battery, and to allow operation of the system if the battery goes bad and power from the solar/wind sources while isolating the bad battery so as to not drain everything to death.
RFB
When I was running AM, my nighttime signal dropped from a mile in certain directions during the day to 1-2 city blocks (certainly significantly less than 1/4 mile).
FM, even with Canada's relaxed field strength rules, gets you a lot less than a mile (1/2 to 1 km at best) but it's relatively consistent throughout the 24 hours.
My AM runs daytime only for this exact reason. It goes nowhere at night. 1610 would be wonderful if there wasn't a 1600 in town.
My Current home at 1650 gets clobbered by Arkansas and El Paso at night.
Good thing I'm also on FM!