Hi,

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

73's

Pjotr

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.

The metal hardware is well constructed. It uses stainless steel hose
clamps to clamp the tubing. The antenna to mast clamp is large enough
to handle a wide range of masts up to at least 2".

Make sure to get the holes in the stub insulators lined up. doing the
assembly on a flat floor or driveway should be sufficient.

I've only had a chance to do a very fast check. All bands but either
17, or 12 meters...(I said it was a quick check and I don't remember
which band) show very low SWR over the selected portions except the
one. I have made no adjustments from the original settings in the
dimension chart.

If you use the proper figures and only use the text as a guide the
assembly is easy and can be done by one person.

I'd either guy it with nylon rope, or use temporary guys to get the
thing installed. It can be a bit unwieldy and more than one person
would want to try to install alone. It is rated for 80 MPH wind
survival. However if installing it on even a short tower I'd guy the
thing as it'd put one terrible load on the top of the tower.

You can easily lift the thing with one hand, but not from one end.
:-))

Now as to the negative...Although the stub insulators are most likely
more than sufficient, I'd like to see them made of a bit heavier
material. They have the *appearance* of being a bit light.

I'd change one step during assembly. I would not install the feed
line connection box until *after* doing the counterpoise installation.
It gets in the way of tightening several of the screws, but it's not
impossible. Just an inconvenience. However know where you want it as
there is no counterpoise radial installed in that direction.

They don't tell you until the end that if you are not going to be
using the antenna on 6-meters you don't need to install the stub.
They should tell ham that when they are at the point of installing the
bracket.

I'd like to see them include a small tube of antioxidant grease
instead of suggesting you use some.

Once I'm though with the checkout, the antenna is coming down and
getting spray painted with a clear two part paint (Imeron) for
protection. Then it's going on top of a 32 foot tower at the end of
my shop.

I'll let you know how it works out.

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

73's

Pjotr

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)