Howdy folks...
I am finally ready to take the jump to the HF "dark side", LOL. I am reviving an old DX35 transmitter which is peaking out to 65 watts CW and about 35 AM unmodulated, into a 60w light bulb.
Audio stage is where I am now, I have not tried to modulate it yet. More than likely, I am going to hack the Speech Amplifier, modulator and controlled-carrier circuits for a 600Ω balanced line. The power supply is not strong enough to convert to plate mod.
My Audio Chain:
Gates console PGM buss
Optimod 8000 - Composite out feeds my FM, "test" output feeds
Harris Tri-Band AGC
Inovonics 222 NRSC limiter which feeds my MW transmitter
I was a radio engineer and DJ for 30 years. I thought I was pretty well versed in antenna theory. Was I ever wrong! I mean, it's pretty simple to keep an AM or FM broadcast antenna specced (well directional arrays aside) and most of the time, I never thought much about antennas. Any other low-power antennas I've dealt with have been your typical STL/RPU, SW random wire RX and CB antennas. Granted, I was probably more in my niche tweaking audio and processing equipment than phasors and impedance bridges. The more I try to educate myself on all the intricacies of antennas at HF frequencies, the more confused I am getting.
Here's what I have to work with. Small, suburban lot, as outlined below:
DESCRIPTION OF WHAT THIS IS - Straight up is approx 3 to 6 degrees west of true north. It is a total of approx. 165' deep and 70' wide. The teal boxes with aqua outlines are the house and garage, respectively. Ridgepole of house and garage are oriented east-west. House is a bi-level with basement 36" deep.
The green lines are the chain link fences dividing the yards. The left (west) fence is about 80' and the right (east) maybe 90'. They're probably like 36" high except the north, which has 6' wooden picket fence sections on the opposite yard maybe 3/4ths of the width. The fences do not enter the front yard on either side.
There is a medium-sized Maple (35' tall maybe) in the SW part of the "parkway". The white blob in the rear-center is a Tea Tree and the blobs to the left are Rose of Sharon shrubs. There is actually a third one north of those under the drop, but I covered it with grass when I edited the pic to remove the large willow trees we had cut down this summer.
The power/utility drop is the RED LINE. It dissects the yard diagonally from about 40' in the center to the far northeast corner. Utility/power lines run above the north end of the property. A real PITA!
There is a double-height split deck on rear of the house, northwest corner. The high end is to the west, and is about 6' to the floorboards from the ground. In that NW corner of the deck, there is a 15' mast I have my sloper on, as well as a UHF Corner Reflector. I could probably elevate that mast up to about 30' max if I put guys on it. IDEALLY, I would like to put a tower on the middle of the west side of the house, provided I can find one I can afford. Being poor sucks.
I have an old HF ground plane I scrounged that I could hack for low-angle TX antenna. All aluminum and quite old, likely 70's vintage. It is what it is. I could mount it on top of the existing mast. I do not know if it has a loading coil or not, but I suspect it may. When I get it apart I will update as to that.
I have a 6' broomstick helical that I used for my MW TX. It's wound around a 1" PVC pipe and I don't recall what the wire length was. I scrounged the 14g shellacked wire from an old plate transformer with a fried primary. The PVC pipe is wound nearly it's entire length. If nothing else, I could maybe incorporate this as a loading coil in series with the vertical. This would likely be a TX only antenna.
I am really considering an NVIS antenna mounted above the chainlink fence on the left side of the yard. That is a lot easier to use and access than the other parts of the yard.
Another thing I may do in the future is a dipole along the west boundary from tree in front yard to the back.
I do not have much 50Ω coax, mostly shorter chunks. I do have a *bunch* of RG6, probably a couple hundred feet or more. Obviously, the TX wants 50Ω coax. Then, there are baluns, ununs, all that magic stuff. This is where the brain bleed starts.
if this was your situation, flat wallet and all, what would you do?
Topic: 43m pirate TX antenna ideas (Read 2918 times)
