So.. digging around the house looking for stuff, I have about 25' of stranded 16 guage wire, a 24" long 2" PVC and a couple of end caps for it.
Any suggentions on what else I need to make an antenna for the talking house, if I can with this stuff, and turns of the coild, etc? I did a search through the forums, and I could swear this had been covered a million times.. maybe I'm not searching the right stuff? - its going on 1650AM
use your manteca magnum on 1700 khz. put the TH in a weather proof box right below the manteca magnum.
use a balanced wire with two baluns at each end if using unbalanced gear run your audio and power up to TH.
you will need a little extra audio drive than just a consumer level mixer to over come the audio balun losses.
1700 is flooded here,so I'm looking to do 1650...
make a bigger form and add a few more turns along with taps and a air variable cap to the magnum design.
that is a real good antenna design
You can use the Wheeler formula:
L = n²∗d²/(18d + 40h)
where: L = inductance in microhenries
n = number of turns
d = mean diameter in inches
h = height of winding in inches
or, as I did, use ratios to get the right number of turns. Also, I don't see an advantage to larger diameter, 4" works well for me. I think better changes would be to use white PVC drain pipe, which has an 1/8" wall as opposed to 1/4" wall Black ABS. The wall thickness and black pigment and ABS material is more conductive...which is what you DON"T want...because we're going for an air coil.
Also, because the power is negligible, I used 16awg fine multistrand insulated wire (most recommend laquered solid wire) for a couple of reasons: 1) Fine stranded wire in larger gauges is harder to find, but allows for more skin effect, and 2) If it is 'close wound' (a kind of misnomer in this case), the insulation makes for some separation between winds, which can help decrease the effects of eddies in the coil.
I did not use taps because I spent time recalculating the number of turns in several different ways...enough to know it would be very close for my antenna length and frequency of use, and left the fine tuning to resonance to length adjustment. But things change and I'm thinking of a large minimum range
True, the thinner-wall sewer pipe and stranded wire are less strong, but I slathered a number of coats of PVC sealer/glue over the whole thing, which made up for it. I use nylon guys. The thing has so far withstood winter storm winds of about 55mph.
I hope this makes sense and helps.
Oh - hey, since we are on the same freq, do you mind telling me the # of winds you used on that 4" pipe?
I don't remember now, but I adjusted it from the Magnum down a bit to 1650kHz. My objctive involved the same principles as the Magnum, mainly no taps. My 'theory' is that with this kind of extreme low power, make things simple, accurate, and efficient ... in this case, no multiple taps.
However, I think my next project will likely be a 10" dia. cage monopole with heavy gauge coil with hat and stinger combo at the top. The TX will be built to fit inside the tower, along with DA converter and digital optical cable to carry the audio to the TX. IOW, the antenna, coil, TX, and converter are all one unit, with a pure pristeen optical digital audio feed (no possibilty of RFI, nor will it radiate anything).
But I have a slew of obligations to catch up on before I can start work on it.