[TowerTalk] Cheapskates

Roger (K8RI) on TT K8RI-on-TowerTalk at tm.net
Thu Dec 18 23:26:28 EST 2014



Today's rigs give the "operator" more control over their signal than at 
any time in history.  IOW they give the opperator almost limitless ways 
to turn a great sounding signal into something brown and smelly.  Most 
of us do not have the equipment to take advantage of a fraction of these 
abilities properly.  This leaves the "big rigs" a mass of buttons and 
knobs, while the smaller ones end up with menus 3 layers deep with 
results depending on which way you go through those menus.  We now have 
rigs that require you have the "well studied" manual at hand, to get on 
the air.

It's only recently that solid state finals have even "approached" the 
signal quality produced by a pair of old 6146As in a 32S3 or KWM-2, yes 
all this ability has reduced that gain into a loss at the hands of many 
hams.

Receivers have reached the area where dynamic range, bandwidth, and 
sensitivity are well past the limits of useful practicality and are 
bragging rights only.  What do we gain with a receiver sensitivity 
that's a full order of magnitude (or two) greater than the band noise?  
What do we gain by having steep sided 2.8 KHz selectivity where off 
frequency signals are over 100 db down when those signals 5 KHz to the 
side have 20 over signals "IN" your pass band due to IM products only 30 
db down?

Evey once in a while I run into someone complaining about their new rig 
not handling the QRM from the side and unable to understand that it's 
the transmitted signals fault and not their receiver's.  The problem is 
that if all new rigs had IM products at least 60 db down, it'd be 
decades before much difference would be noticed because of the sheer 
number of rigs "out there" that put out poor quality signals.  Still, 
that's where the change is needed.

Antennas have made incremental gains with the only major change being 
antennas that can tune themselves across a range of frequencies.  Still, 
these are subject to mechanical failure as well as lightening induced 
failures and ALL antennas are a number of compromises.

Multi-element antennas produce gain by radiating a signal from one 
element and inducing a current in a "parasitic" element that is either 
in phase or out of phase with the driven element.  The length and 
spacing of the parasitic element to the driven element determines 
whether the parasitic element is a reflector, or director.  You can also 
have multiple driven elements.

Methods of driving and loading elements have been developed, but a 
parasitic array is a parasitic array with efficiency depending pretty 
much on the matching network and the relative size of the antenna, so 
very little has actually happened in antenna design. Some cover more 
band width than others, some have a more elegant matching system, and 
some tune themselves.  Some hams use multi antenna arrays and stacks 
with diversity reception so they use the best antenna at the time for 
the desired contact. Other than that, what's really changed?

73

Roger (K8RI)


On 12/18/2014 12:03 PM, Tom Osborne wrote:
> I finally broke down a year or so ago and bought a brand new radio. 
> That radio sucks with all the menus, etc, and wish I would have spent 
> the same money on a good, used one.  Next time I won't make the same 
> mistake.
>
> I am definitely a cheapskate :-)  73
> Tom W7WHY
>


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