[NLRS] Advice on 2M transverter, bricks

[Cathy James]

Jerry K0CQ wrote:
> Going with a 10 watt transverter fits more PAs that need 10 watts of
> drive for 100 watts or more. 60 watts will way overdrive most bricks and
> gain little but splatter.

If I used a 60W transverter, I would skip the brick entirely.  Otherwise 
there's no point in going
with the 60W DEMI over the 20W Elecraft.

>> I'm currently building a 3-element quad from PVC and copper tubing, and 
>> hoping to get within sight of the theoretical gain for this design (9 
>> dB+).  Is this a reasonable gain figure for weak-signal, or am I going 
>> to find that everyone else is running 5 or 6 element beams?
>>     
>
> Might as well keep that under the bed. Most weak signal stations are
> running 1 to 4 12 to 15 element yagis. at least 12 dBd gain. 9 dB from a
> 3 element is not realizable, not even dBi.

I don't have room to put up anything like that at the home QTH.  It 
would have to be
for portable use only.  My little suburban house and yard is rapidly 
turning into an antenna farm
as it is.  I have no tower and I'm not going to put one up; antennas are 
mostly on TV masts
attached to the house, and at low heights (20 feet or less).  This isn't 
ideal from a
radio point of view, but mechanical and physical constraints win out 
over RF constraints.

The design I am building is closely based on a Cebik W4RNL design buried 
in the following
article:

http://www.cebik.com/quad/2mq.html

Theoretical gain is 9.89 dBi (free space vs. free space), F/B ratio 
exceeds 25 dB.  The
downside is that it is narrow-banded on impedance, so it is only usable 
over a 1 MHz
range.  I plan to tune it to work in the 144- 145 MHz subband.

>  And a quad has a strong cross
> polarized response about 45 degrees from the main lobe that leads to
> much interference from vertically polarized services like pages and
> repeaters.
>   

Interesting, I had not heard that before.

> There is another concept proposed and used by K1WHS, he calls it the
> large vertical array. Its a stack of 4, 8, or 16 short yagis. The yagis
> are selected (5 elements, 9.1 dBd claimed) for a 10 dB beam width of 90
> degrees. Four stacked (5.5' spacings, so taking 16.5' of tower space)
> gives nearly 15 dBd gain in the main lobe, comparable to a 5 wavelength
> long boom yagi and much easier on the rotor.

Interesting approach, but I'll never have room for anything like that.

> I caught some better conditions during the June contest when I tuned up
> that yagi at 6' elevation above ground, and I worked well around the
> midwest and sporadic E out to Connecticut.
>   
That bodes well for use of larger antennas portable, which I could 
certainly do.
> While more than a 3 element is very desirable, 2 or 4 5 element begins
> to be respectable and ANY antenna up and used is better than waiting for
> the better antenna to come along.
>   
Amen, brother. :-)


Cathy