K1JJ tuner coil core, antenna software and Zepps

[VE7 Kilohertz]

Well, as Frank mentioned, now that it has snowed and is constantly below freezing, it's time to get out there and start playing with new antennas and feedlines. 

I installed NECWin Pro last night and am reading thru the manual to try to get up to speed on it's use. Looks like a very powerful program.

Did some more reading of previous posts re: K1JJ big tuna and I think I shall build one, as I have lots of coils, 1/4-3/8" copper reefer tubing and vacuum variables at hand. I am posting a few pics for you to peruse. Do you think these coils would work? They are very heavy duty and have lots of nice slip on flat clips for tuning. I was thinking of 3 in series, with the link coil mounted inside the middle one. Not sure what inductance these are but they are about 6-8" in dia. and 10 turns each. Maybe need 4-5 of them in series?? That would be getting pretty big and may be better just to make a 40 turn coil from copper tubing. Which brings me to my next question. I don't like having big coils just hanging in space and would like to wind the coil on ABS or PVC. Would there be any detrimental effects to leave this plastic form in place?

ABS looks cool as it is black and with the copper coloured tubing would simulate the look of a 1978 Black T/A (aka Smokey and the Bandit mobile) 

I have buckets of big ceramic standoffs and copper straping so making it safe and able to handle 750W should be easy.

The Zepp has been working well and I can actually tune it now on 160M and 75M, with the roller inductor either maxed out or right out of the circuit. I just want something a little more versatile and faster to tune.

Cheers

Paul

[flintstone mop]

Yup Paul,
BRAG about the Canadian legal limit. The U.S. Hams have to have better antennas to compete with your signal.
I'm getting a little fire under me for a magnetic loop antenna for 160M. The Europeans are really into these things. I guess real e$tate is at a premium over there.
Fred

[VE7 Kilohertz]

So, any thoughts on leaving the PVC or ABS in as the core to support the copper tubing?

Cheers

Paul

[KD6VXI]

I've used the PVC as my core support at HF frequencies, making chokes out of feedline (coaxial).

I did a LOWfer station as a final  project in electronics class in high school.  I seem to remember that we had problems with some of the 'coil forms' we used (PVC and ABS).  I recall it was the paint / stain / whatever they used to color the material with.

Quick test in order, throw the material in the nuke for a bit.  If it gets warm, it is no good.  If not, throw a few thousand watts at it and see what happens.


--Shane

So, any thoughts on leaving the PVC or ABS in as the core to support the copper tubing?

Cheers

Paul

[W7XXX]

Hi Paul, I have used ABS as an insulator to support a 40 meter vertical made from rigid copper tubing. Worked fine no problems. In the past I have used the black poly pipe as the insulator inside an adjustable gamma match, it also worked fine. I am still entertaining the idea of making a helical wound 160 vertical on 4" ABS. I don't have the room for a good radial system, so I am not sure it would be worth the time and expense. I am using lower 75 mtr freqs as the 3870 group is just too large. I am anxoius to hear your Bauer on the new now 8 tube homebrew dual conversion receiver. I am on mornings 0500 and afternoons 1330 usually below 3850. Are you able to load the Bauer that low without going inside and retuning? 73, Sam

[VE7 Kilohertz]

Hi Sam,

Thanks for the info on ABS. That's great news and I will use it for the coil support. If I had used my (failing) memory, I would have remembered I used ABS as the coil form for my new plate choke for the Bauer. It works FB.

Yes, the 3870 group has changed it's characteristic in the last year or two and isn't what it used to be a few years back. I rarely hear any good techincal discussions and like you say, the group gets to be so large there is no time for old buzzard transmissions.  I have been on 160M more this year than 75M and enjoy the smaller group, and the time is better for me too. I can't seem to stop my day at 3pm to get on 75M to talk with my local friends.

The Bauer will do 3860-3890 without too much problem but beyond that I need to change the PI cct values. I will try it on 3850 and see how it works.

Thanks and best 73

Paul