[PSDR] November HamWAN update
Bart Kus
me at bartk.us
Mon Dec 3 17:11:29 PST 2012
Hello,
A quick & dirty update for everyone.
1. HamWAN Labs has undergone a major upgrade in terms of microwave
equipment capability. New equipment added to support testing:
1. HP 8566A 100Hz-22GHz spectrum analyzer with 10Hz RBW and -130dBm
DANL! This unit has a broken 1st stage converter though, which
drops its output level by 50dB when the converter gets warm.
I'm working on replacing this converter, but for the time being
I've externalized it so it's kept cooler than the inside of the
analyzer. This keeps it working nicely. Pictures of
externalization, and specan bottom:
https://lh4.googleusercontent.com/-xz21Of-xjJw/UL1A_kUNztI/AAAAAAAAAdk/gW_fhk4Yxrg/s889/IMAG0099.jpghttps://lh3.googleusercontent.com/-20eacBqZwOM/UL1A_hPYwaI/AAAAAAAAAdk/cjk2FXavTBo/s889/IMAG0100.jpghttps://lh3.googleusercontent.com/-jhKxUaU-hD0/UL1A_nTADCI/AAAAAAAAAdk/J1ZSe1HsOiw/s889/IMAG0101.jpg
2. HP 8672A 2-18GHz signal generator. Still waiting on shipping,
but this will provide very steady test signals so narrow band
testing can be done. The present YIG oscillator setup has a
4MHz bandwidth and I cannot stabilize it without throwing it
into a PLL. Plenty of other benefits to the HP generator here,
such as GPIB control, built in attenuator, and AM/FM modulation
capability. Picture of signal generator:
http://www.surplus-electronics.co.uk/urchin/assets/images/_mod/20111109_152447.7646.586.800.-1.85.jpg
3. A 4-axis CNC milling machine! With adjacent channel
interference being an issue, and the cost of microwave cavity
filters astronomical, I believe this is the best/cheapest way to
do channel filtering, by home-milling microwave cavity filters.
It's also useful for PCB fabrication. Pictured below. 4th axis
not shown.
4. Lots of various mill/drill bits for the CNC mill, as well as a
light tachometer.
5. Lots of new SMA interconnects/adapters to make working @
microwave easier.
6. Boonton 2500 DC Calibrator. Finally found this authentic unit
for a reasonable price. This puts an end to the HamWAN DC
Calibrator project, but I'm leaving the pages up since they
contain lots of good tolerance analysis work. May be useful later.
7. Boonton 25A 1MHz RF calibrator. It was really tricky
calibrating the thermocouple sensor (4200-8E) using this since
it needs to be cal'd @ 50MHz. This took a few days. But the RF
calibrator is a very precise unit, and it calibrates diode
sensors (such as the 4200-4E) beautifully. I was able to use
this RF calibrator as a standard and then reflect the power
levels up to a couple different RF sources @ 50MHz to do the
actual thermocouple calibration. The +20dBm power level range
calibration is only approximate as a result of my process, but
it's good enough and the best I can do. Who would have guessed
you have to account for LMR400 losses @ 50MHz over 4ft? Well,
it's true! There's a measurable loss. Here's the unit:
8. 10MHz Rubidium Frequency Standard. Sadly this unit is not
working. Trying to get a replacement mailed out. It will allow
for very precise frequency measurements and can be used to align
microwave gear. Here's a picture of the stock unit, and my
attempt at getting it to work by cooling it:
9. A linear 1.3-10GHz 0.6-10dB 1W attenuator.
2. GPIB control has been established with all 3 important instruments:
the power meter, the frequency counter and the constant current
source. Faced some challenges with getting the Boonton 4200 and the
EIP 451 to do GPIB, but they were overcome. Always remember to
configure your terminating characters properly! With all 3
instruments being controllable now, the next step is automating
sweeps. The YIG oscillator is not very leveled across its spectrum
so I'll have to subtract an error curve. The spectrum analyzer
supports this operation internally, but I have not yet figured out
GPIB control of that unit so that I could extract the data/graphs
from it.
3. Cougar site acquisition has stalled, and I'm not pushing it. I want
to be damn sure that the sector antennas can co-exist without
interfering before throwing anything up there. Deployment can be
expensive. Here are the guts of the most promising antenna:
4. I'm on a HamWAN vacation all week to be able to finish up these
tasks. Couldn't ask for a better time. :)
5. All HamWAN Labs equipment is purchased out of my own pocket and is
not considered HamWAN assets.
6. HamWAN balance is $350 with only one recurring donor. Technically,
HamWAN can't throw up even one site should Cougar become available.
While I don't mind spending money on HamWAN Labs stuff, I'm gonna be
pretty strict about HamWAN network gear itself being funded out of
not-my-pocket. It doesn't scale. You can paypal money to
donate at hamwan.org or use the website. I've also got a "PayPal Here"
credit card scanner on the way so the next time I present on HamWAN
subjects, I should be able to take donations right on the spot via
my phone + the card reader.
7. Managed to hack a little bit on the rotor for antenna pattern
testing. It's a synchronous motor in there, and I got it to run @
10Hz without saturating the core. :) With this slow rotation,
angle measurement can be done based on time instead of more trickly
angle encoders.
8. HamWAN almost has $2mil site liability insurance. Benjamin is
working on the details with the ARRL. This should cover all the
sites we deploy onto under 1 policy.
Ever onward!
--Bart
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121203/bc5bb912/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: IMAG0099.jpg
Type: image/jpeg
Size: 81458 bytes
Desc: not available
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121203/bc5bb912/attachment.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: IMAG0100.jpg
Type: image/jpeg
Size: 72569 bytes
Desc: not available
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121203/bc5bb912/attachment-0001.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: IMAG0101.jpg
Type: image/jpeg
Size: 95367 bytes
Desc: not available
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121203/bc5bb912/attachment-0002.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: IMAG0108.jpg
Type: image/jpeg
Size: 141222 bytes
Desc: not available
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121203/bc5bb912/attachment-0003.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 20111109_152447.7646.586.800.-1.85.jpg
Type: image/jpeg
Size: 94918 bytes
Desc: not available
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121203/bc5bb912/attachment-0004.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: IMAG0105.jpg
Type: image/jpeg
Size: 95323 bytes
Desc: not available
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121203/bc5bb912/attachment-0005.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: IMAG0107.jpg
Type: image/jpeg
Size: 73017 bytes
Desc: not available
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121203/bc5bb912/attachment-0006.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: IMAG0106.jpg
Type: image/jpeg
Size: 133650 bytes
Desc: not available
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121203/bc5bb912/attachment-0007.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: IMAG0102.jpg
Type: image/jpeg
Size: 124013 bytes
Desc: not available
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121203/bc5bb912/attachment-0008.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: IMAG0110.jpg
Type: image/jpeg
Size: 119523 bytes
Desc: not available
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20121203/bc5bb912/attachment-0009.jpg>
More information about the PSDR
mailing list