there are some isotron AM's on ebay. the whole series from the 600 to the 200B $248.00 + modest shipping.
thinking of snagging one with paypal to experiment using part 15.219. the 200 / 200B are about 3 meters tall and the 200 (not B model) covers 1600-1799 kHz, B model covers 1650-1799 kHz.
according to RFB they are decent antenna's for 15.219 when used with TH's, SSTRANS's and other 50 ohm capable 100mW DC input transmitters.
remember you are using all 3 meters in this antenna so the TX must be right at the antenna and the antenna really needs to be ground mounted or elevated mounted using a pvc insulator over metal mast as these ground via their mounts and the FCC won't give you a pass on that one. ground mounted is best though for absolute compliance when at all possible.
i will probably sit on it for a while and one day i will say screw it and just grab one 🙂
got an AMB-200 coming
Should prove interesting to see how it performs. I think I considered an Isotron for 40m a few years ago. I just ran some wire up as a dipole instead. Keep us posted.
medium wave band and HF bands. yes they even have one for 11m/CB
this sucker is huge (13 ft), lots of metal (aka: Capacitance) and a very large coil (high Q).
i need a larger mast to mount it my mast is shy of a couple of feet. i think it will pass FCC muster unless you get a absolute hardline agent. i doubt a reasonable agent will ding you for an extra meter (if he even notices), an extra meter does not add that much to the far field erp. my conclusion although i have no current way to test is when coupled with a properly adjusted sstran amt5000 and the amb200 being properly tuned and placed at ground level over a bunch of ground radials with the amt5000 put right at the base of the antenna is that this thing will outperform anything out there although the bandwidth will likely be very very small as the Q on this thing is probably very very high. might be higher than the AM1000 antenna system so i can't garuntee a very good sounding signal but if a talk format is what you are doing this will likely be a good performer for music not so much. just my opinion based on examining it's construction. when i get a big enough mast and some property to test my theory on i will come back with some actual test data unless someone like tim in bovey beats me to it 🙂
Let us know how it works out. I wonder if it is directional.
have a suitable part 15 legal transmitter coming that is 100mW input and will load into 50 ohms. we shall see how the Isotron stacks up against a traditional base loaded whip antenna over a ground plane.
... we shall see how the Isotron stacks up against a traditional base loaded whip antenna over a ground plane. ...
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For a better understanding leading to a fair and useful comparison of such tests, suggest reading the two links shown in the URL below on a page at the Isotron website.
The fact that they are linked on that website is surprising, as those papers don't appear to be very supportive of some important performance claims made for the Isotron.
https://isotronantennas.com/index.php?main_page=page&id=19&zenid=13536e6ca20585f7cad3a1873fd78dc3
The ground in this case is the radiator?
Wow be careful with this antenna, how big did you say this antenna was? 13 feet?
I see a ground mounted install in your future Part 15 Engineer.
Scratching me head at this one, not at all what i expected from an Isotron.
Barry of BBR World Wide
i kind of believe i will come to the same conclusions as the article. my visual inspection of the antenna design kind of backs that up.
it is simply a base loaded shortened vertical with top and bottom capacity hats.
looking at it i am sure it relies heavily on gorund lead radiaiton.
my Talking Sign from @AR should be here next week it is 100mW input to final and loads into 50 ohms as well as a 3m wire antenna.
we shall see how it does in the real world.
i have it assmembled and sitting in garage waiting to be tested 🙂
it will be tested @ as close to ground mounting i can get it.
it puts out 92mW into 50 ohm load at 1630 kHz.
i might get to range testing with the ISO 200 antenna today.
since it is so easy to switch between wire and a50 ohm antenna i will likely do comparison range testing between the simple wire and the 200.
the ISO 200 doesn't do much better than my horizontally mounted procaster. and yes i laid out 3 ground radials and did run the TS-100 in 50 ohm mode.
i got about 150ft-200ft before splatter from 1600/1690 (both 1/4 mile away) and lots of qrm overtook the signal.
by contrast my procaster here does 50-100ft
I bought the ISO-200B but have not assembled it yet. I am still waiting for my AMT-5000 to arrive which I expect next week. Even then I plan on using the 5000 with a whip or long wire antenna before I use the ISO-200 to get some kind of baseline before I try the ISO-200. Claims for the 200 are that it does not need a ground. Really? Not using a ground system appeals to me because it's difficult to go a foot deep on my property without hitting rock but I can't imagine getting better or equal performance without a ground system. Relating to the 3 meter rule I do have the option of ground mounting the antenna system in my back yard which rises above the 2nd story of my home. I might be able to mount it there with a shallow ground system and remain in compliance. Has anyone done serious comparison testing of the ISO-200? Thanks. Jim
Contact Craig directly at his online store The K1CRA Radio Store
www.k1cra.com and you can save about 20 bucks vs. going through eBay.