I've a 22-foot sailboat with a typical VHF marine antenna.

With the advent of AIS (http://en.wikipedia.org/wiki/Automatic_Identification_System), marine antenna manufacturers are now making "wideband" antennas (http://www.shakespeare-marine.com/antennas.asp?antenna=5215) to accommodate this new functionality.

Conventional wisdom seems to be that boaters can use a 2m radio with a marine (156-162 Mhz) antenna, relying on the loss inherent in the length of coax to handle the mismatch.

I've not used my current antenna for 2m, but had given it serious consideration. Another alternative was to build my own wideband or multiband antenna. However, I was thinking that these new AIS antennas might be a better solution given the price (about $40 retail) and "wideband" designation.

Thoughts anyone?

Brent
W1NCH

I've a 22-foot sailboat with a typical VHF marine antenna.

With the advent of AIS (http://en.wikipedia.org/wiki/Automatic_Identification_System), marine antenna manufacturers are now making "wideband" antennas (http://www.shakespeare-marine.com/antennas.asp?antenna=5215) to accommodate this new functionality.

Conventional wisdom seems to be that boaters can use a 2m radio with a marine (156-162 Mhz) antenna, relying on the loss inherent in the length of coax to handle the mismatch.

I've not used my current antenna for 2m, but had given it serious consideration. Another alternative was to build my own wideband or multiband antenna. However, I was thinking that these new AIS antennas might be a better solution given the price (about $40 retail) and "wideband" designation.

Thoughts anyone?

Brent
W1NCH

Going to put a multiband dipole (40-30-17-10m) up in my attic. Got some questions:

1) I'm using parallel-wires, separated by insulators (probably sections of PVC pipe). It will be insulated wire (from Home Depot, 14AWG, 500ft spool). How much distance should separate the individual wires? Two inches? Four inches? Does it make a difference?

2) Will I be able to use the 40m section for 15m, or would I need a separate set of wires? Given that a 40m dipole is equal to a 1-1/2 wave 15m antenna, what will the feedpoint impedance be? I'd like to use this antenna without a tuner if possible.

3) When tuning the individual wires, is there any sequence or method? Obviously there will be some interaction between the wires, so tuning one may effect the others.

TIA,

Brent
W1NCH

I'm winding a loading coil around a PVC form for a short, portable antenna.

Should I use insulated or bare wire?

The coils will be well spaced, so I guess I'm wondering about performance. Some of the literature I've read suggests insulated wire to reduce the inter-winding capacitance.

On the other hand, bare wire would make it easier to tap the coil for the various bands.

Suggestions anyone?

Don't let antenna restrictions prevent you from operating HF; magnetic loop antennas are small and surprisingly effective.

There was a great how-to article in the May 1994 QST for a loop antenna of about 3' diameter that works from 12-30m. If you have ARRL membership, it can be accessed online at http://www.arrl.org/tis/info/Loop-H.html.

MFJ makes a few loops too; the MFJ-1786 works 10-30m and the MFJ-1788 works 15-40m.

Don't forget; an all-mode will give you one-half of the needed equipment for satellite work.

Why go through the trouble of drilling through the foundation?

Correct me if I'm wrong, but aren't most homes are built with the floor joists sitting on top of the foundation? In my home, these joists are 2x10 and butt against another set of 2x10s along two sides of the house. The dryer and gas furnace vents are drilled through and secured here.

In my case, I just drilled a 2-1/2" hole (starting from the outside - I used the dryer vent as a reference point) through the siding into this joist; then put a 90-degree PVC elbow on facing down as a weather head and caulked around it just to be safe. Doesn't leak, works well and only took about 1/2 hour to do.

Sure beats trying to drill through concrete and then weather-proof that!

Here are a few that I'm aware of:

http://www.qsl.net/k5dh/index.html
(click on "My home station" on the left, then scroll down on the right. You'll find a number of tube-based rigs available)

http://www.qsl.net/wd4nka/form.html
(scroll down on the left and you'll find a number of tube-based projects; I'm currently gathering parts for "A 40's era MOPA")

http://www.arrl.org/tis/info/tranrcvr.html
(Unfortunately, most of the projects here are for members only, but it's a good idea to be a member. If for no other reason than to be able to get at all the projects that are available here http://www.arrl.org/tis/tismenu.html)

As noted, some searches on Google will net more. You may also want to pick up an old ARRL handbook; the ones from the 1950's probably have the most to work with.

Brent
W1NCH

Last year I picked up a couple of homemade frequency counters from an estate sale.

I recently opened them up to replace the power plug with a standard computer recepticle (they have built-in power supplies) so I can use standard cords and noticed that they were built from etched circuit boards.

As is the case with some circuit boards, there is type identifying the board(s) and the project. Each of the boards has its own code:

CW-LW4
CW-LW2 (this is on the LED counter board)
6GVC

And at least one has the project name and maker of the boards:

ARRL DVM/Counter
Circuit Board Specialists, Pueblo, CO

Obviously, this is a DVM/Counter project that probably appeared in some ARRL publication. However, I've looked at the ARRL web site and checked in the few ARRL Handbooks that I have, but found nothing that matches. And as far as I can tell, Circuit Board Specialists doesn't exist anymore.

Does anyone know anything about this particular project? I'd love to get a copy of the original article so I know the capabilities and limitations (and to have some idea of how it works in case it needs repair in the future).

Brent
W1NCH

Any 2m FM radio can do simplex, your HTX-242 is no exception.

These are the simplex channels on 2m:

146.415
146.43
146.445
146.46
146.475
146.49
146.505
146.52 National Simplex Calling Frequency
146.535
146.55
146.565
146.58
147.42
147.435
147.45
147.465
147.48
147.495
147.51
147.525
147.54
147.555
147.57

BTW...If you don't have a manual for your HTX-242, ask around; someone probably has one they can copy for you.

73,

Brent
W1NCH

P.S. - It is "73" not "73's"; as "73" means "best wishes" "73's" would mean "best wishes's"

The August 2003 issue of Wired magazine had an article on the Biefield-Brown effect and antigravity. NASA has proven that it requires an atmosphere (i.e., no antigravity properties).

It is pretty fascinating stuff nevertheless. See also:  http://www.americanantigravity.com/

Any idea where to find that article? I've found some things on the internet, but most of it describes what can be done, not what to do.

I recently purchased a set of "Rabbit" and "WaveCom" Part 15 wireless TV transmitters.

I am going to do some experimenting with these for 33cm and 13cm ATV. With some external antennas and simple amps, they should be a cheap & easy way to get into ATV and put some use to our UHF/microwave frequency allocations.

Anyone in New England (specifically the Southeast region) interested in ATV?

I recently purchased a set of "Rabbit" and "WaveCom" Part 15 wireless TV transmitters.

I am going to do some experimenting with these for 33cm and 13cm ATV. With some external antennas and simple amps, they should be a cheap & easy way to get into ATV and put some use to our UHF/microwave frequency allocations.

Anyone in New England (specifically the Southeast region) interested in ATV?

I'll second the MFJ-9406 suggestion, and endorse eBay with the caveat that you need to exercise caution and restraint.

I purchased a used MFJ-9406 on eBay for $125 plus shipping. It is definitely used--some of the front panel markings are worn, but I knew that when I bid on it. It works great--I used it w/a homebrew 3-el yagi in my attic to work a guy in Georgia (about 875 miles) last month.

This was a great deal, but you can spend too much on eBay if you're not careful. The important thing to remember is to set your spending limit and be patient. I've seen the same radio go for wildly different prices just a few weeks apart. Much depends on what the seller is asking and how many bidders there are.

73,

Brent/W1NCH