Another mini-DXpedition is in the books - thanks to everyone who took time
to work us in Rhode Island!
NC1I, KA1QFE and I went to the site the previous weekend to get everything
set up. All went pretty well until we attempted RX tests and found the RX
system not working. Three hours later figured it out: the 1 amp fuse for
the 12 VDC to the feed mounted preamp had blown. We had earlier checked the
voltage at the BIAS-T and feed and measured the correct voltage - we even
swapped the preamp with a spare. The DC power distribution is a Rig Runner
unit (with Anderson power pole connectors) and has a small LED to indicate
when a fuse it blown. We were measuring voltage through the LED - but it
wouldn't pass enough current to power the preamp. Ugh!
NC1I and I returned on Thursday and fired up the station. As usual we had
our European friends all ready to work us . and the screen was bright with
signals. About two hours and 20 QSO's later all went quiet when our 20 kw
diesel generator shut down. (This is a field day like operation with no
connection to the mains / grid.) Took approximately three hours to
troubleshoot that problem - luckily in daylight and with good weather
conditions. The generator controller shut down due to low output voltage
(just over 180 VAC and it should have been 220 VAC). We actually
experienced this problem before - caused by failed capacitors in the
generator voltage regulation circuit. Got a bypass working and ran it with
the lower output voltage.
We ended up also running the camper's 5 kw generator as well because the
Alpha SPID controller didn't like the +/- 90 VAC input and the on-board
camper air conditioner needed the higher voltage.
Even with the unexpected down time on Thursday we ended the day with more
QSO's than we had expected.
Come Friday morning we woke to heavy overcast skies and pretty chilly temps.
During the day it actually struggled to reach 16C / 60F. As I didn't bring
a jacket and only had short sleeve shirts we actually turned the heat on in
the camper as the equipment we were running just didn't generate enough heat
(especially with the kw amp mounted at the base of the tower).
During the day we had off and on rain but nothing detrimental for our
operation. Right before our lunch break we were fortunate to work PA3DZL -
Jac was using a single 67-element yagi and 120 watts - nice QSO!
After lunch we made our first experiments with WSJT-X v1.9 and using the
QRA64 mode completed QSO's with Bob KA1GT. The rain tapered off and later
in the day KA1QFE and KU1RT flew by to make some aerial photographs of our
location. It was a pleasure to close out the day with some setting moon VK
and JA contacts.
After a good rest we returned back to the site for Saturday's operation. As
expected it was a bit slower but enough activity that we were kept busy. At
our lunch time W9JJ joined us and stayed for the remainder of the operation.
This allowed Frank NC1I to make the 2+ hour drive home to work us from his
Frank stayed home overnight on Saturday and drove back to Rhode Island on
Sunday morning. After he picked me up at the hotel we heard a strange noise
in his vehicle which got worse by the time we got to the site. Turns out it
was a front wheel bearing and we had to have his vehicle towed back to his
home garage. Good thing this did not happen when we were towing the 2700+
kg / 6000+ pound trailer with generator, tower, dish, etc. back home!
Compared to Friday, Sunday's WX was hot and miserable 35C / 95F - probably
even worse if you were standing on the side of the highway!
Our Sunday activities were constrained by personal schedules - we had
originally planned on breaking down early and heading home. We were
fortunate to be able to get on for a couple of additional hours at our
Sunday moonrise and put a few more contacts in the log.
At the end of the operation we had 67 initial contacts, 9 stations worked on
CW, 22 DXCC countries and 7 US states. This exceeded our expectations - and
- exceeded our QSO count last fall as N1H from New Hampshire. Over the next
week or two we'll try to gather all our photos and choose something for a
QSL card. Probably will take a couple of additional weeks after that before
we have them in the mail. We will QSL 100% direct to your QRZ.COM address -
if you would like your card sent elsewhere please drop me an email off-line.
If you'd like to send us a card please send to NC1I either at his QRZ.COM
address or via the bureau if that is easier. Envelopes and donations are
One thing that was different for us during this DXpedition: it was our first
use of the Elecraft K3S rig. Previously we had been using a Yaesu
FTDX-5000MP. The big difference: < 2 kg versus 25 kg! We were very pleased
with the WSJT performance of this radio: it certainly performs as well as
the 5000. We had a little more difficulty on CW probably in part due to the
fact that we had no familiarity with operating CW with this rig. At some
point I'll set the rig up at the NC1I QTH and get a better handle on the CW
RX settings. We also ran less power this time being more conservative with
the amp and its power supply sitting outside at the base of the tower and
the (almost) summer sun.
Another project I hope to accomplish this summer will be building much if
not all the shack components into rack-mount cases that will facilitate
setup, breakdown and storage of the equipment. This would include just
about everything you see on the operating position table along with all the
components that are mounted on a board that we clamp to the back of the
Without saying special kudos to KA1QFE who's contributions include not only
the camper (caravan) that we operate out of but also the outboard generator
and antenna tower and mounting system that he designed. And yes - he also
threw in a couple of comfy arm chairs for us to relax in as well. (After
all, we are old timers!)
We hope to do something again before the end of the year - stay tuned for
more details on when and where.
Just a reminder, my moonrise in FO13 is around 0250utc Saturday and around
Last night Frank NC1I was nice enough to loose some precious sleep and do
some testing via the moon. His power was down about 4dB and he still came
in loud and clear on the speaker(decoded signal was only - 19)here in FN03
to a single V-pol 28el yagi and a calculated NF of 1.8dB. Measured power
output at the feed was 210watts and received a - 18 report from Frank. At
this test, degradation was - 3.9.
Hope to hear many of you this coming weekend.
73 de Peter
I read a paper prepared for the November 2011 DUBUS which described a
very nice loop feed design for 432 MHz. This design looked good so I
decided to build it.
My dish is 3M prime focus f/d = 0.37. I have been using my 3M dish
with a patch feed for 1296 MHz with good results. Sun noise = 10 db.
I removed the 1296 MHz patch feed and installed the larger 432 loop
feed and its baffle/choke. I installed the loop feed as close as
possible to where the patch feed was installed. Installed VSWR is
My first-night QRV, I worked DL7AVP, HB9Q, and NC1I - all easy QSOs.
My TX signal reports were -20 to -15 (JT65) with 150w at my feed. My
preamp is in the shack at the moment and the receive performance, as
expected was not good.
Today, I move the preamp to the dish and my results were unexpected.
With the preamp in the shack, I see no noise floor increase at low
elevation and no sun noise. Noise at the receiver is flat regardless
of antenna position.
When I add the preamp at the dish, my ground noise is 5 dB higher than
the cold sky. However, my sun noise is only 2 dB. Do you think that
my dish is improperly illuminated? Maybe the feed is not at the focal
point and the dish is under-illuminated?
I need to fix this problem because I will quickly run out of
super-stations to QSO. :)
73 - Paul - W2HRO
Just a reminder, tonight I'll be on starting moonrise till moonset (if you
keep me busy and I don't fall asleep)
Moonrise Saturday local 2320/Sunday 0320utc
I will be on 432.072 regardless of direction of moon I will be running 1st
period for full pass.
Hope to get some smaller stations in log, all stations worked last night
were speaker copy. I am in a very very quiet location.
Sorry I don't have my adapter 1/8" to 1/4" for CW.
If I don't seem to be around(fallen asleep maybe) feel free to make my
phone ring or text message to (416)358-5481
I won't answer to avoid charges on your end, it'll be a wake up call, just
73 de Peter
Nice to HEAR your signals last night.
In the log:
NC1I FN32 - 24dB( Possibly first ever to work ZONE 2 on 432 EME)
HB9Q JN47 - 18dB
DL7APV JO62 - 18dB
OK1DFC JN79 - 18dB
OK1KIR JN79 - 23dB
W5LUA EM13 - 22dB
Sorry to the VK, I think it was VK4CDI, I just didn't wake up in time for
our common window. When I woke up, you had just left. I will be back again
tonights for moonrise at 2320 local/ Sunday 0320 UTC.
I will operate on 432.072 always 1st sequence.
73 de Peter
Memory fault is mine. This is the page I was recalling, however it
discusses probe length VS isolation, rather than diameter.
My apologies for misleading.
I don't remember where I saw it, but someone tested probe diameter VS
isolation between the TX and RX. Perhaps someone with a better memory
has a link to this document. I don't know if that is extremely
important unless you are seeing LNA damage.
I have always used a piece of the outer shield of UT-141 with no harmful
> -------- Original Message --------
> Subject: [Moon-Net] Question about coupling probe of OK1DFC septum feed
> From: Bob Atkins <ka1gt(a)hotmail.com>
> Date: Thu, June 28, 2018 2:11 pm
> To: "moon-net(a)mailman.pe1itr.com" <moon-net(a)mailman.pe1itr.com>
> Most of the construction articles for the OK1DFC septum feed seem to use coupling probes with a 6mm diameter. Typically something like 40 - 43mm x 6.3mm (1/4"). Is there a technical reason why the diameter of the probe is so large. The resonance is determined by the distance from the rear wall of the closed waveguide, the length of the probe and the setting of the tuning capacitor. Presumably the diameter will have a small effect on the tuning, but only a small effect and the tuning capacitor compensates for that. So why 6mm rather than 2mm or 3mm? My thought is that the probe diameter really doesn't matter much and 2mm, 3mm, 4mm, 5mm and 6mm would all perform similarly once tuned to frequency. You probably wouldn't want to go too thin, especially on the TX port where it may be handling significant power I guess.
> My reason for asking is that I'm tuning up the feed for best return loss. I'm currently using a 1.5mm coupling probe because I had 1.5mm silver plated copper wire available. Return loss is good (-40dB). Am I missing something by not using a 6mm coupling probe? I don't think I am, but wanted to get other opinions since I may be missing something.
> Bob, KA1GT
I'm trying to build/buy rotary which is precise enough for 10GHz,12GHz and
maybe later for listen 24Ghz.
I tried to built one by myself for azimuth but the gears (angle gear 1:60)
having to much free movements and the dish have free movement for a few
Any suggestion are welcome with yours experience?
I want to experiment with dishes from 90cm to 120cm
Ill be up for full moon pass as long as I have callers. If I happen to fall
asleep. Make my phone ring hihi. (416)358-5481
73 de Peter
On Fri, Jun 29, 2018, 3:55 PM <moon-net-request(a)mailman.pe1itr.com> wrote:
> Send Moon-net mailing list submissions to
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> Today's Topics:
> 1. Re: something better than JT65 and FT8? (Bob Atkins)
> 2. Re: 5760 Septum Feed Coupling Probe question (H Dee)
> 3. Re: 432 EME from ZONE 2 TONIGHT! (Steve Bell)
> 4. Re: CAT control of FT-897D anyone? (Bob Atkins)
> Message: 1
> Date: Fri, 29 Jun 2018 18:18:21 +0000
> From: Bob Atkins <ka1gt(a)hotmail.com>
> To: "Moon-Net is an e-mail reflector intended for discussion and
> announcements concerning amateur radio moonbounce communications."
> Subject: Re: [Moon-Net] something better than JT65 and FT8?
> Content-Type: text/plain; charset="iso-8859-1"
> It's a nice idea, but unfortunately not one that works (or is usable) in
> this application. It's like those TV crime shows where you have an
> incredibly blurred and noise image and with a couple of mouse clicks the
> image is sharp and noise free. It just doesn't work that way. You can
> certainly take out background hiss on wideband audio signals and improve
> perceived audio quality, but audio signals have a huge signal to noise
> ratio, maybe +80dB for high quality audio. Even at a noisy +30dB you can
> statistically remove noise and have good signal left. Butthat's not what
> you are trying to do here.
> At an SNR of -25dB (2500Hz) if you statistically remove the noise (over
> 2500Hz bandwidth), you statistically remove the signal along with it. If
> you knew EXACTLY what the noise was, then you could remove it, but by its
> very nature it's random and you can only apply statistics to it. If you can
> handle the math (I can't) see
> There's also the very important fact that although you hear a lot of noise
> and no signal, WSJT is looking (listening) in a much narrower bandwidth and
> does "hear" the signal. It looks at the fourier transform of the signal and
> it does, in essence, subtract the noise, but over a bandwidth that's the
> same as the signal (tone) width. So it's doing "noise reduction" on the
> signal already, by subtracting what it thinks is the background from what
> it thinks is the signal.
> If you want weaker signal reception than JT65 or QRA64 can give you the
> obvious option is to reduce the data rate (by lengthening the
> transmission). There's nothing magic about 60 second overs with 48 seconds
> of signal. You could have 2 minute periods or 5 minute periods and you'd
> get a lower detection threshold. 5 minute overs were standard practice in
> the days before digital modes. It could take 30 minutes to an hour to
> complete a QSO with "O" reports in both directions. JT9-30 has 30 minute
> periods and can detect signals down to -40dB, but requires very stable TX
> and RX frequencies and is intended for VLF, LF and HF operation. It looks
> at a bandwidth of only 0.4Hz, I don't know if it's usable for EME at VHF,
> UHF and microwave frequency which stability would certainly need GPS
> locking and maybe sub Hz accuracy Doppler tracking would be required.
> From: Moon-net <moon-net-bounces(a)mailman.pe1itr.com> on behalf of Lyle
> Dysinger N4QH via Moon-net <moon-net(a)mailman.pe1itr.com>
> Sent: Friday, June 29, 2018 11:09 AM
> To: moon-net(a)mailman.pe1itr.com
> Cc: Lyle Dysinger N4QH
> Subject: [Moon-Net] something better than JT65 and FT8?
> we all know jt65 digs out the weak signals in the noise than the ear
> cannot hear. but what about getting rid of the noise so that we can audibly
> hear the those weak signals. adobe soundbooth CS5 and 6 does just that. why
> aren't we using such an application? seems to me more experimentation with
> this could lead to no more heated up finals, and more personalized QSO's.
Is anyone using CAT control of a Yaesu FT-897D?
When I connect it up I see a 1-2dB increase in the noise floor with the antenna looking at cold sky. I can even see it with the RX terminated with a 50 ohms load, so I don't think it's RF radiation from the cable. I've tried two PCs and I see the added noise with both of them. I don't need any software running to see it, just and active COM port and the cable plugged in. I'm using a commercial cable with a built in USB to serial adapter which the PC recognizes as a Prolific USB to Serial. I don't have the cables and connectors to plug the FT-897 into a true serial port, and I don't have a true serial port spare anyway. I don't have the cables and connectors to try a different USB to serial adapter either at the moment.
Is this something intrinsic to the FD-897D? Or maybe to the USB to Serial adapter? You might not notice it on HF or for troppo work on VHF, but it's very obvious when using the FT-987D on 144mHz as an if for 1296.
If anyone has seen this and found a fix I'd love to hear about it.