On Sun, 01 Dec 2013 13:05:23 -0600, amdx wrote:
I'm only a little masochistic, I'll suffer some but unless it's
something I really want I'm easily distracted.
For me, it's the math that causes the most suffering. I have 3
calculators, one PC, and a Mac on my desk, and I still can't get the
right answer. Maybe I should buy an iPad?
It is impossible to achieve enlightenment without suffering. In other
words, things become more obvious after you screw everything up,
destroy some equipment, and injure yourself. It becomes very plain
how something works after it tries to kill you. You can do it slowly,
rapidly, or periodically, they all work. In some cultures,
flagellation has been shown to be effective. The only problem is that
this all applies to the models of antennas, not the actual
performance. That's pure magic.
I might have back in the 70s I thought about using a modulated laser
to do the wood burning pictures. Might have been there early enough.
Just talked with a laser engraver yesterday, prompted my mind.
btw, could you make PCBs with a laser?
Sure. No copper required. Just burn some tracks into the FR4/G10
with the laser. They should be sufficiently conductive to work with
low power circuits using solder paste of connections. However, to be
sure, you might want to measure the ohms/square of carbonized PCB
material. However, you're behind the times. The hot ticket are
printed PCB's using an inkjet printer and nanoparticle inks. I wrote
a rant on the topic in a mailing list last week. Unfortunately, the
archive is for members only.
Light reading:
http://dl.acm.org/citation.cfm?id=2493486
http://www.techweekeurope.co.uk/news/silver-ink-solution-for-cheaper-faster-flexible-circuits-54967
Years ago, I thought I had a better idea of PCB construction. I would
roll a rounded point over the unplated G10/FR14 PCB forming groves for
traces. I would then fill the grooves with conductive solder paste
using ordinary silk screen techniques. When I tried it, it actually
worked. However, the process was slow because anything faster than
maybe 1/2" per second would burn the PCB from the friction.
Ok, one data set! I have the transmitter then a 3db att. then my LPF
then another 3 db att. and the rubber ducky. I walked 250ft before noise
showed up, then I went back and ran the antenna straight out of the
transmitter.
As you might think things did not work out as expected. I did not get
as far with just the antenna. About 10 or 15ft less.
Ummm... a good question would be why that's happening. Plenty of
possibilities including that your yard is an RF black hole. However,
my guess(tm) is that nothing is very well matched to 50/75 ohms and
the coax, attenuator, and LPF are radiating (leaking). You should
probably fix that although 250 ft is more than I would have expected
with a commodity receiver.
Heh-heh. Make me rich and a broken 8555 can be yours. I have 3 of
them but only 1 works, so this will be a repair job. I can probably
fix it, but don't have the time or incentive.
http://www.LearnByDestroying.com/jeffl/pics/home/slides/test-equip-mess.html
You'll find that the hp8554B plugin (0-1200MHz) is more useful for FM
BCB use.
I'd need to have a working unit, I'd have major problems with a
repair. Can't I do with the 8555 anything I can do with the 8554?
I charge extra if it works. The 8554 goes to 1.2Ghz. The hp8555a
goes to from 10 MHz to 18GHz. With an external mixer to 43GHz.
They're quite different plug-ins. You'll need an external hp8445b
preselector to get rid of spurs and strong interfering signals.
I'll dig out the plugs tonite and see what I find. Maybe I'll get
lucky and one will fix itself.
Incidentally, the mixer likes to blow up in the hp8555a when you
transmit into it. The fix:
http://www.k3pgp.org/hp8555a.htm
I feel like you getting even for the MFJ1800 :-)
I've thought about that. Please inspect any packages you receive from
me with a bomb sniffer before opening.
I have a 300Mhz scope, just to complicate things. Measured 7.5Vpp.
Sooo, I get 0.143 watts, so much for spec's.
I was going to suggest you try a 75 ohm load, but it looks like the
xmitter is specified at 50 ohms.
http://www.elecsky.com
http://www.czhfm.com/datasheet/CZH-05B-Manual.pdf
Looks like the rubber ducky is tuned to the FM band.
http://www.elecsky.com/index.php?main_page=product_info&cPath=10&products _id=5
If I install the rubber ducky in place of the 50 ohm, I get 8.3Vpp.
If you run it open load, you'll probably see even more voltage. The
power measurement is only valid with a proper 50 ohm dummy load or 50
ohm antenna.
Later, I'll connect my MFJ259 to the rubber ducky, and see what it says.
The display will probably say "give up and get a real antenna".
Ya, maybe, but I'm running low power through 6db of attenuation with
two walls and an aluminum screened porch between my problem area and the
transmitter.
Now you tell me. Perhaps all the junk in the way might have an effect
on the signal level? Instead of a new antenna, perhaps moving the
transmitter or running a longer coax run might be useful?
Minor problems, like I say I can move the radio
5ft and solve the problem.
Too easy. Moving the radio or antenna does not demonstrate how they
work. Without suffering there can be no enlightenment.
I just turn up the volume control to get the same effect.
The neighbors would think I'm weird, I listen to Science 360,
Gunsmoke, Phil Hendrie, what a train wreck!
Yeah, you have a problem. Perhaps if you play what the neighbors
prefer to hear, they might be more tolerant of your bizarre listening
habits. My usual mix is 60's electric acid rock, New Age, and
classical music. I haven't determined if this is the result of brain
damage, or the cause.
Need to go take over for my wife at the business, I'll reread what you
said here and look at links when I get to work, it's a tough job
(well, not really) but somebodies got to do it.
Bah Humbug (T'is the season to be grumpy).
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558