I just bought an Index Labs cabinet from Derek- very pleased and packed well. It took a few emails back and forth- but in the end I it worked out very well.

Dale W4OP

While I have never owned the antenna, it certainly seems they should be adjusted for lowest VSWR.
Be aware though that an antenna of this type without radials will have lots of common mode current on the outside of the coax- so the coax  also becomes part of the antenna. Change the coax length or how it is routed and the VSWR changes.

Dale W4OP

The original hubs were sand cast and  considerably stronger than the  later die cast hubs. The holes in the center of the hubs were a perfect snug fit for the Avanti booms once the ears were tightened down. Your best bet is to wait for another set to become available.

Dale W4OP

If you are not 100% positive about what you are doing- Take a close up photo of the area you are working on before removing anything.

Dale W4OP

Some here may be interested in 3 videos I have placed on YouTube:
 

http://www.youtube.com/watch?feature=player_detailpage&v=O077VLhmCD4   Homebrew RX

http://www.youtube.com/watch?feature=player_detailpage&v=HPilAT8anG8     Cubic 103 + station accessory

http://www.youtube.com/watch?feature=player_detailpage&v=Phbgz1J0Xa8     Atlas 350XL + station accessory

I hope to have the Halicrafters FPM-300 MK II + station accessory video up first of December

If I have posted these before, just ignore.

Dale W4OP

They can't even spell Moxon- what  makes you think they have the gain correct?

Dale W4OP

Spot on Paul,
I see  a difference of 25KHz wider on 80M when going from #14 gauge to 1/4" conductor size in EZNEC

Dale W4OP

Hi Dave,
Thanks. I am slowly putting a CD together of restoration techniques. Many I have never seen before- as in taking a dent out of a plastic knob..
Dale W4OP

Hi Ken,
A 450' Beverage will work just fine- even on 160M. That was about the length of mine when I lived in FL. They are now closer to 550'.
Don't confuse the Beverage ground with the ground system a vertical antenna requires. You are looking for a ground that is stable in value not necessarily a low resistance that a vertical requires for efficiency.  An 8' ground rod available at the big box stores should be sufficient.

The Beverage achieves its low noise characteristics through directivity. Mine work just great for stations at any distance as long as:
1. They are roughly in line with the Beverages front lobe
2. The main contributors to band noise- eg thunderstorms- are not also in this line.

Beverages model easily in EZNEC- doing this will give you an idea of the beamwidth for a given length and frequency.

I have put up rotatable flags, rotatable loops etc and nothing comes close to the Beverages.

GL,
Dale W4OP

There is so much wrong information on the internet with regard to the double bazooka, it is difficult to know where to start.
There is no theoretical reason why that design would be any quieter than a regular dipole. Second, the stubs acting as conjugate matches to the antenna impedance and thus yielding wider bandwidth is also false. The wider BW is a result of fatter conductors and loss in the stubs. Here is an excellent paper on the double bazooka:
http://vk1od.net/antenna/DoubleBazooka/index.htm

Walt Maxwell and Frank Witt have done some nice mathematical treatments illustrating the fact that the stubs cannot perform as bazooka manufacturers would have you think.
Finally, there is no reason that a double bazooka's design is such that it  does not benefit from a balun or isolation choke.

Save yourself  some time, money and antenna weight and put up classic 1/4 lambda monopoles.

73,

Dale W4OP

For the same crystals, the  in/out impedance goes down quickly as the filter BW narrows- so I would think it would be difficult to judge Rin and Rout solely based on frequency.

As an example, a  6 pole filter I built from 5MHz rocks has  Rin and out of just under 1K. The same crystals configured as a 500Hz filter has Rin  and out of 85 Ohms. Different topologies  will likely yield different results- but I believe the trend remains the same.

Dale W4OP

Hi Larry,
re PTI: Maybe not. I have had them build  VHF crystal filters in very small quantities. Maybe you will get ahold of a guy who has been there a long time and recalls your filter.

The Zin/Zout may well be complex for a perfect conjugate match, but I think many mfg just specify a terminating resistance.

I have worked backwards from the schematic as long as I can locate the small signal paramters of the active device the filter looks into. In my experience, most are bilateral- so if you can calculate one side, you have the other.
GL,

Dale W4OP

Have you tried contacting PTI?

Alternatively, if you have a network analyzer or access to one, you could try some different turns ration toroidal transformers and  see what results in the lowest insertion loss.

Dale W4OP

AB3LD posted that the resistor SHOULD be 1K- so don't go looking for a 100 Ohm.

Dale W4OP

Thanks Greg,
I'll check when it comes in. I have decent stock of Molex- I was just hoping to have the cable ready when she arrives.

Dale