CCC,
As you know, the 160 meter geniuses (W8UVZ, KD9SV, and K8GG) did very well in the 160 contest last weekend. These gentlemen are superb engineers and 160 ops, and so their advice is the best possible. Here's my take on the summary of what they came up with from nine days of 1.8 MHz experience at the station. K8ND: Please correct any errors I may have made.
1. The TX antenna (Inv L) performs well and is the best possible, given the real estate constraints. We were heard well in Europe, JA, VK/ZL, and the signal in North America was almost as good as ZF2 and FM, both of which are much closer. Recommendation: Keep the Inv L, keep adding radials, eventually replace the RG-8X with real coax.
2. The US/JA Beverage works MUCH better (about 10 dB less noise) when it is moved about 200 feet away from the house toward the hotel. This gets the feedpoint and transformer away from the coax messenger cable and a host of other miscellaneous low level sources of noise near the house. Once moved (temporarily) away from the house, there was virtually nobody in NA who could not be heard. The Topband reflector comments are that the PJ2X ears were 100% excellent. Recommendation: Move the Bev permanently 200 ft from the house and install direct-bury coax out to the feedpoint. Do NOT lengthen it, as a longer Bev will probably be too narrow off the front. I was obviously NOT happy that they de-installed our nice, permanent Bev, but I have to eat crow on this because the performance of the relocated Bev was dramatically better. We have a big project to do now to make this antenna permanent.
3. Their temporary phased pennant antennas with preamps heard Europe "as well" as a Beverage would. Recommendation: Either install a pair of permanent phased pennants, or finish our Eur Beverage project, either one.
All of this falls under the heading of fine tuning needed to move the station from a good one to a great one. Let's do it and keep improving!! :)
73,
- Geoff
First is the Davis RF RF-9914F, which is deemed direct burial
due to the waterproof and non-contaminating nature of it's jacket.
It's $0.59/ft in lengths 100-499 feet, and $0.57/ft in lengths
500 - 999 feet. Details here:
http://www.davisrf.com/ham1/coax.htm#buryflex
The other option is Times LMR-400DB, but it's around $.74
per foot. Competitor Davis says it requires special connectors,
but I could not find any indication of this on the sites below.
Times sells standard (Teflon) PL-259s for them.
http://www.texastowers.com/lmr.htm
http://www.timesmicrowave.com/telecom/pdf/lmrdb.pdf
The difference is the flooding compound in the LMR-400DB,
which should make it last much longer in the presence
of rodents, rocks, plant spines, and water.
From the TowerTalk Mailing List, here is one man's analysis,
which seems to me to be quite reasonable:
http://lists.contesting.com/_towertalk/2002-October/051773.html
The main enemy of buried feedlines is water. Rodents open an
ingress, and the water actually slays the feedline. At Signal
Point, water is not too much in evidence, and a slightly leaky
jacket shouldn't hasten the death too much.
Geoff, I have transformers and I believe George also has a couple. The only
question would be which type of connector do you need? I built both BNC and
"F" type. Another point...perhaps a 1/4 L of wire ran above ground (on the
bushes same height as the beverage) and left open-circuited (in series with
the termination resistor) would probably present a lower impedance than a
small "Crows-foot" would...either is okay but having seen first hand the
difficulity of the vegetation there do which ever is easier. Moving the
feed point away from where it was made a huge difference in noise and
performance...we were able to work many 3rd-4th layer stations...de gary,
kd9sv
From: gary nichols [mailto:kd9sv@comcast.net]
> Sent: Friday, January 31, 2003 13:21
> To: Jeff Maass
> Subject: Re: The Bev Project....
>
>
> The wire is #22 and the cores I dont know...I buy one at hamfest
> and take it
> home and test. If it has adequate reactance and looks inductive (not
> resistive) with a few turns ie 4 turns greater than 150 ohms inductive
> reactance at 1.85 then I go back and buy the quantity I need.
> (probably 72
> or 77 mix, 43 mix requires too many turns) Typically a bev xfmr
> would be 12
> turn sec 4 turn primary for a 9:1 xfmr. The supports we used for the
> Pennants were the push-up mast for one and the K9AY mast for the other. We
> put the Teflon RG62 in the suitcase with the K9AY stuff. The Pennants in
> phase spaced about 240ft had increadable rejection off the sides. When we
> switched to EU the US virtually disappeared all but extremely strong
> stations and EU would jump out at us. They were very quiet but require at
> least 20db of pre-amp. I'm glad you bought two of the DXped
> model FES's as
> we used both and keyed them from the run station which allowed the other
> radio to listen on any of the RX antennas, even on the transmit freq while
> both radios were protected...it worked better that I could have
> anticipated.
> BTW, vy2zm barely beat us while having 12 more hours of operating time..de
> gary
> ----- Original Message -----
> From: "Jeff Maass" <jmaass@columbus.rr.com>
> To: "gary nichols" <kd9sv@comcast.net>
> Sent: Friday, January 31, 2003 12:46 PM
> Subject: RE: The Bev Project....
>
>
> >
> > Gary:
> >
> > For information for one who didn't get to see the transformers you
> > used, what sort of cores are you using? What size wire?
> >
> > 73,
> > Jeff Maass jmaass@columbus.rr.com Located near Columbus Ohio
> > USPSA # L-1192 NROI/CRO Amateur Radio K8ND
> > Maass' IPSC Resources: http://home.columbus.rr.com/jmaass/index.html
> > Circleville USPSA/IPSC: http://home.columbus.rr.com/jmaass/pcsiipsc.htm
> >
> > > -----Original Message-----
> > > From: gary nichols [mailto:kd9sv@comcast.net]
> > > Sent: Friday, January 31, 2003 11:19
> > > To: Geoff Howard; jmaass@columbus.rr.com
> > > Cc: W8UVZ@voyager.net
> > > Subject: Re: The Bev Project....
> > >
> > >
> > > Geoff, I have transformers and I believe George also has a
> > > couple. The only
> > > question would be which type of connector do you need? I built
> > > both BNC and
> > > "F" type. Another point...perhaps a 1/4 L of wire ran above
> > > ground (on the
> > > bushes same height as the beverage) and left open-circuited (in
> > > series with
> > > the termination resistor) would probably present a lower
> impedance than
> a
> > > small "Crows-foot" would...either is okay but having seen
> first hand the
> > > difficulity of the vegetation there do which ever is easier.
> Moving the
> > > feed point away from where it was made a huge difference in noise and
> > > performance...we were able to work many 3rd-4th layer stations...de
> gary,
> > > kd9sv
> > > ----- Original Message -----
> > > From: "Geoff Howard" <ghoward@kent.edu>
> > > To: <jmaass@columbus.rr.com>
> > > Cc: <kd9sv@comcast.net>; <W8UVZ@voyager.net>
> > > Sent: Friday, January 31, 2003 9:29 AM
> > > Subject: Re: The Bev Project....
> > >
> > >
> > > >
> > > > >Covered this above. Again not sure how much noise was elimated by
> > > > >changing the xmfr and, at the same time, moving the feed point out?
> > > >
> > > > Aaaaaahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh. THAT makes sense, and Gary
> > > > confirms it in another E-mail. The overhead stringer: lots of
> > > feet of icky
> > > > oxidized galvanized guy wire, not bonded to itself or to the towers
> > > > particularly well. Makes SENSE to get away from that puppy!!!
> > > > >>
> > > > >> 3. Do you want me to extend it from 540 feet to 1080?
> Recommended??
> > > >
> > > > OK, also makes sense, we won't extend it and take a chance on making
> the
> > > > lobe too narrow.
> > > >
> > > > On the transformer, I don't know if the ICE one has
> isolated windings
> or
> > > > not. K8ND: DO YOU KNOW??? If the answer is no and you guys have
> > > one we can
> > > > buy, fast, I'll take it down and install it on the 11th. No donation
> > > needed
> > > > -- you "donated" plenty enough to the station already with your
> > > payment....
> > > > :)
> > > > >
> > > > >It's abt 750' now. Guess I would try a different xmfr and
> different
> > > > >feed point(away from the coax entry and the stringer) maybe still
> near
> > > > >the house and see what you think. You may be able to quiet it down
> > > > >without moving the feed point out 200'. But you will
> still fight the
> > > > >problem of having tx antenna radials outside the fence and
> under the
> > > > >beverage wire and the resulting noise pickup.
> > > > >
> > > > >Leaving the length at 750' or less, will keep its beam width wide
> > > > >enough to cover the entire US. At 2 wvl or 1000', you may
> > > find you chop
> > > > >off NE or WC, hi.
> > > > >
> > > > THX for the advice!!
PS to Jeff: A good reason for have the US beverage feedpoint away from
> >the house, I think. After we reconnected it to the original feed point,
> >the noise appeared to jump several S units.
It appears to be between 2-3 S units or nearly 15 db and that will
certainly make the difference between hearing that new mult (maybe WY
with 50 w and a short wire?) You can hear the buzzzzz of the noise once
the wire is reconnected to the house location.
Geoff, one thing George didnt mention that I noticed was that the messenger
cable that supported the coax from the towers was tied to all three towers
and anchored to the house at the point where the beverage transformer is
located. That brings noise pickup from all the antenna "stuff" in the area
right to the beverage for amazing noise pick-up. The other thing I noticed
is that CCC was using high temperature anti-seize compound (which is
probably non-conductive) to prevent oxyidation and perhaps increase contact
resistance. What I referred to was called "Al-no-ox" and is used mainly
where aluminum wire connected to another type of material to prevent
oxyidation. It also allows telescoping sections of aluminum to come apart
at a much later date...IMHO, de gary, kd9sv