On Fri, 26 Sep 2003 00:58:45 GMT, Roger Halstead
wrote:

On Thu, 25 Sep 2003 19:52:25 +0200, "Pjotr"
wrote:

Hi,

Any one good or bad experience with the Hy-Gain AV640? What about the
mechanical construction?

I *just* came in from setting one up on an 8' support to check the
settings.

My impressions:

It is well constructed and rugged. The aluminum tubing is of a heaver
stock than any I've seen so far in multi band verticals. It is
sturdy. You can support it horizontally from one end with no more
droop than the much shorter elements on a triband beam.

A bit more information:...

No, I've not been out working DX like crazy with it, but I have
finished tuning, listening, and have made a few observations:

As I mentioned in the prior post the SWR looked good on all bands, but
I wanted to get a bit more bandwidth out of 20 and 40. Actually 40
looked good, but it was basically 1:1 at the band edge so I figured I
could shorten it a tad and raise the upper frequency limit.

I think I mentioned that the 40 meter sloper ran within 4 or 5 feet of
the top and just to the south of the AV640.

At any rate, my wife Joyce (N8JBW) came out and helped me take the
vertical off the temporary mount so I could adjust the length of the
radiator for 40 and prune one inch off one of the top hat wires for
20.

Both had the desired effect, but when I dropped the 40 meter sloper
for a check the band width on 40 narrowed a bit. I now have from the
bottom band edge to about 7.175 between the 2:1 points. On 20 I now
have the entire band between the 2:1 points.

So, now I'm waiting to get the rest of the bare #2 copper for the
ground system...The 32 foot tower at the end of the shop is not
grounded. I want to add two 50 foot runs with 4 8' ground rods and tie
the end of the one run into the ground system for the big tower. I
also need to put in a ground rod right outside the wall from the
station in the shop and then ties that into the big ground system as
well. I currently have about 400 feet of bare #2 wire cad welded to
20 ground rods. I'll be adding about 175 feet more #2 wire and 6 more
ground rods. I use a piece of 3/4 inch thin wall conduit as a
hydraulic drill. Go in 8 1/2 feet, and then just drop the ground rod
in. Dig away from the top a bit and then cad weld the wire and rod
together. (I'd sure hate to have to remove all that ground wire and
ground rods.)

Then it's install a good 144/440 duo band vertical on top of the shop
using a small tripod.

I also need to add a 2" steel conduit run from the rigs in the shop,
up over the small garage door, back down along the edge of the wall,
around the corner and about half way across the west end before going
through the wall to the tower.

I have lots of work left before cold weather too. I need to get all
the cables "inside" the big tower, and install an inverted-L, half
slopers, or shunt feed the tower for 160.

To top it off, the center support on the 6-meter yagi has come off and
I have to let the whole works down to the top of the tower. That
requires about a half day tower climb and a lot of work with a come
along. In addition I have to remove the rotor from the tower so I can
lower the mast down through so I can work on the antennas.

As long as I have to go that far, I'm going to replace the LMR
flexible pig tails from the antennas to the top of the tower.

Ohhhh...yah....I have to finish the cat 5 cable run from the shop to
the computer room and router. Right now there is a 130 foot run of
cat 5 running out a basement window and laying on the ground all the
way to the shop.

Roger Halstead (K8RI EN73 & ARRL Life Member)
www.rogerhalstead.com
N833R World's oldest Debonair? (S# CD-2)