[CQ] 2 meter radio donation for NB?

[Bill Paul]

> > We actually don't even need the note to satisfy our legal/license
> > obligations.  But, honestly, I'd rather make it nontrivial for drunk 
people
> > in the space to be douchebags on IRLP.
> > I'd really love to put up a single antenna before I leave town for a week
> > next Thursday.  What all would we need to solve for this?  Is it just a
> > matter of the feedline?  Since we're only putting up a single antenna, we
> > don't need a switchbox and all the associated problems.  We can add that
> > part later, in a little weatherproof container, etc.

> An antenna for 144 Mhz? Should be simple to build from an SO-239
> chassis-mount or similar, as previously discussed.

I'd still like to see an HF setup at the space too. I think we have enough 
height and roof space for a decent wire antenna, though I'm not sure about 
available mount points. The antenna I have at home is an Alpha Delta DX-CC, 
which covers 80, 40, 20 and 10 meters, and a few spots in between. It's about 
80 feet long, and works in either an inverted vee or flat-top dipole 
configuration. I think inverted vee is preferable, but that requires a mast 
to lift the center point high enough, which may be tricky. (A metal mast can 
affect the antenna's resonance, and wind must be taken into account too.) 
Once errected though, you just need some 50-ohm coax to connect it to the 
rig, and you're ready to go. (I use an antenna tuner to smooth it out, and to 
use it for SWL on other bands.)

The good news is that this antenna works well, and I think you can buy one 
right from HRO in Oakland (that's where I got mine, but that was a few years 
ago). The bad news is that it costs about $160.

One other thing that will almost certainly be a problem is eletrical noise: 
between the florescent lighting and all the electronics, I expect a lot of 
QRN. At my place, I mostly have issues with noise in the evening. During the 
day things are pretty clear on all bands, but at night, 40 meters is covered 
with about 7 s-units of constant buzzing. I'm not sure of the source -- I 
suspect it's either florescent lighting in my building and the one next door, 
or possibly the street lamps. Regardless, it's a major irritant.

I ended up ordering an MFJ-1026 noise canceler, and I have to say, it works 
pretty well. I just received it on Friday and I've only played with it a 
little over the past couple days, but when it works, it works great. For best 
results, you really need a second antenna to pick up the noise signal, and 
I'm going to try putting one up over the holidays. The little built-in whip 
antenna and pre-amp are only useful if the noise is strong and/or highly 
localized. Luckily, that happens to be the case with the 40 meter buzzing. It 
takes a little practice to tune it right, and I sometimes need to re-tune it 
if I shift far enough along the band, but once I find the sweet spot it nulls 
the noise right out. Suddenly, signals that were totally obscured are legible 
again.

Again though, the bad news is with this thing is price: it costs $200. Still, 
if we manage to actually scrounge up an HF rig for the space and noise does 
prove to be a serious problem, I may be inclined to donate one.

Oh, speaking of which, I upgraded my antenna tuner recently, which means my 
old MFJ-941D is now sitting idle. It's only rated for 300 watts and the built 
in SWR/power meter doesn't work anymore, but the tuner circuit works fine. (I 
was using it with a separate SWR/power meter previously.) If we end up with a 
radio that doesn't have an internal tuner, I'd be willing to donate this.

-Bill


-- 
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-Bill Paul            (510) 749-2329 | Senior Engineer, Master of Unix-Fu
                 wpaul at windriver.com | Wind River Systems
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   "I put a dollar in a change machine. Nothing changed." - George Carlin
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