Nice TROPO Propagation on 10GHz

We have experienced nice Tropospheric radio propagation here in the Midwest of the United States of America. Many stations made unusually long contacts on HAM Radio bands from VHF to SHF frequencies. I was lucky too .. made my longest 10GHz contact so far (842km - 526 miles):

Mike MK0T confirmed our contact by sending his QSL card

Back side of Mike's QSL card

Mike finished setting up antennas on his tower just days before the event

I have made contacts with others too, this card is from Gedas,
contact was over 509 km (318 miles)

More details about our activities with more pictures can be found here and here.

Even more 10GHz DX

Worked Gedas W8BYA using Rain Cell mover Iowa. The distance of 576km (360 miles) is currently my 10GHz record.

More success on 10GHz

I am happy to show several more QSL cards for QSOs on 10GHz:

W8BYA

Rain Scatter - 515 and 519 km (322 and 324 miles)

WB0LJC

Direct Tropo 322 km (202 miles)

W0ZQ

Direct Tropo 318 km (199 miles)

Contest results

I am not really attending contests to win, more for fun and to test the technology. However, it feels good to receive certificates like this one:

Boys with Toys 2

My last posting was about using my RIGOL Spectrum Analyzer with frequency range up to 1.5GHz to show characteristic of a 10GHz filter. That little test made me wonder if I can use the same Spectrum Analyzer to display a signal in the 10GHz range on that analyzer. Obviously, I have to mix the signal down below 1.5GHz using a transposing signal from another synthesizer.

I have used my 24GHz transverter with 11.88GHz local oscillator, because that signal is conveniently fed to a connector on the transverter's front panel. The same mixer from my previous test (IF range only 0-150MHz) was used for the first test today:

Yes! It really works! My ELCOM on the left side is programmed to 10.805GHz (+13dBm) and the gray transverter on the right side delivers 11.88GHz (+10 dBm). Difference of these two signals is exactly 1.075GHz which is what we see on the analyzer. What we also see is the signal level below -40dBm. Hmm ...

I have tried to "zoom in" and changed the RBW ratio on my RIGOL from 1MHz to 300kHz. Signal still looks nice and clean, just not too strong:

Can we do something about the attenuation? Of course we can. I tried 3 things:

• Find better flexible cables
• Replace flexible cables by Semirigids
• Use different mixer

Luckily, I have bought good sized bundle of these flexible black cables with SMA connectors cheap on eBay. Maybe I could find some better pieces in that bundle? Tried and ... the signal strength improved +30dB:

Wow! This is almost perfect! Maybe Semirigids will make it even better:
 

Hmmm, not too much. Only about 2dB. Surprising, really. These black cables are RG-178 which is OK but not as good as semirigid, at least in theory. Whatever ... let's try another mixer:

Nice! Improvement about 8dB! This mixer has IF range 0-2GHz, but it has apparently been exposed to salty water somewhere. I have bought it cheap on eBay. Lets try better one:

No surprise here, less than 2dB below zero. This mixer behaves as expected. Note that I am feeding it LO signal 11.88GHz about +10dBm and the test signal is 10.8GHz about +13dBm. My RIGOL has internal attenuator of 10dB, so the conversion loss in this case is 13 - (10-2) = about 5dB. That is certainly very acceptable!

My next test will be with a Harmonic Mixer (same thing, but the mixer will generate harmonics from a strong base signal to be able to display higher frequencies, such as 24GHz). But that will be the topic for some other day.

73 Herbert
AF4JF

Boys with Toys

Even at my age of 55, I still feel like a boy when it comes to my electronic (not to mention radio electronic) toys. Especially if my friends keep encouraging me by sending me links to interesting articles on the Internet. Like the document (tnx OK1DXD) where I found following picture:

Nice ... especially after finding dual mixer (two mixers with integrated LO power divider) on eBay:

The seller stated max frequency 18GHz and max IF frequency 150MHz. Well, I overstepped the IF maximum almost 10x and the mixer still worked, so I hope that RF inputs will accept 24GHz.

Now, what to test? Easy pick. I have found a nice waveguide filter on 10567.5MHz:

So, I have located couple of cables, not really suited for 10GHz but at least with SMA connectors, and connected everything together:

Where to get LO signal from? That was easy too - my favorite ELCOM synthesizer provided +13dBm on the frequency of 11GHz:

So far so good ... but will that thing work? I have turned my RIGOL analyzer on and activated the Tracking Generator - and YES, it worked:

Let's try to zoom in to check how steep the filter is:

Pretty good, actually. The passband is flat and only ~40MHz wide. Looks like good filter for general use. With this mixer, I should be able to re-tune it to 10368MHz easily.

Of course, I need to calibrate the "Y" axis. No idea how much attenuation came from the mixer itself. Some definitely was introduced from the measuring cables ... still work to do on my side. I will also try to use the same principle (different Local Oscillator and maybe different mixer) for 24GHz.

73 Herbert

MUD 2016

Microwave Update 2016 will take place in St. Louis this year. Click on this link to find more info.

73 Herbert
AF4JF

Another Synthesizer Issue

I have published my findings with a MICROSOURCE synthesizer here some time ago. That synthesizer is working fine, along with several  other ELCOM LCDFSL-1201 units in my shack. I thought that ELCOM interface is pretty transparent - until I decided to use LCDFSL-1101 programmed for 10.8GHz (10.368 + 432 = 10.8). Well, it isn't.

I have browsed Internet for a while and discovered that many others would like to know how to program that unit. There even is a new controller board for it on a web site in Australia. Hmm .. maybe later, perhaps in winter time. For now, I have found easier solution. Use ELCOM DFS-1101 instead.

The DFS-1101 does not have connector for external reference. There is an internal Xtal used (I believe 100MHz) instead. This unit uses funny frequency calculation: you have to divide the wanted frequency by 5 and add 1024 to the result. In my case (need 10.800GHz):

10 800 / 5 = 2160

2160 + 1024 =  3184 ..... 31 84 00 is the code the interface needs to generate 10.800GHz

I will keep looking for a solution compatible with my LCDFSL-1101 unit. Until found, this cheap DFS-1101 will do the job.

 DFS-1101 unit (left) with my test board with PIC (WW2R design)

Frequency ~ 10.800GHz, voltage 14.7V (before stabilizers), current 646mA.

Unit works with +6V (some ELCOMs require 8V)

My Microwave Activity

I wasn't very active since my last posting on this blog ... in fact, I wasn't active at all. Only made several dozens of QSOs on 160m during winter months. My job keeps me busy and often out of town for weeks without end.

Looks like this is about to change soon. I should be able to return to my hobby and work on all my delayed ham radio projects (along with house maintenance, of course). Here are some of them:

• 24GHz transverter
• New 10GHz station with 3ft antenna and TWT amplifier
• Beacon for 23cm

I have obtained two TWT amplifiers. One for my home QTH, another for my portable station. Pictures will be here on my blog site soon.

73 Herbert

MAD (Microwave Activity Day) on 7/6/2013

The SLAMS group participated on another Microwave Activity Day (MAD) on Saturday July 6th, 2013. I went to my usual location, YMCA parking lot in EM48sq, together with Mel K0PFX and Armand, KD0PXF:

I was set up for 10GHz (dish on the left side), 23cm and 70cm - mostly because this was a first test on few 15el. Comet antenna. It worked well and, even better, this antenna is easy to assemble/disassemble in field. I am going to replace my 12el. Cushcraft with this one and use the Cushcraft at my house for Packet Radio 9600Bd.

Detail of my 23cm gear laid out on a table:

I have experienced the same problem with my transverter - it was overheated even when taken out of the car! Direct sunshine  is able to heat the box to high enough temperature to trip the PA thermal protection. I will have to do something about that before next contest ...

73!

2013 ARRL JUNE VHF QSO PARTY

Once again did some of the SLAMS members participate on a VHF+ contest. I have set up equipment for 144/432/1296/10368GHz in my usual location at YMCA in Westport, EM48sq.

The location actually is identified by following Maidenhead grid designator (according to my GPS): 

EM48SQ58AX

It was one of the hot days, so common in St. Louis. Temperature only 85F, but direct sunshine. I was quite dehydrated in the evening. Even my 23cm transverter didn't like the sunshine and started tripping the temperature protection on me. Covering the box with newspaper fixed the problem, but it gives everybody an idea how hot the day was.

Best achievement for me today was ~200 miles QSO on 432MHz with Zack W9SZ using my 11el. portable Yagi and <5W of RF output from my FT817. I have also worked Zack on 144 and 1296MHz today, but not on 10368MHz.

my usual setup

antennas "from behind"

another view of my setup

That "eggbeater" worked fine

even on my 200 miles QSO

with W9SZ on 144MHz.

This contest always "opens the season". I will post some more pictures from future contests here as usual.

73 Herbert

AF4JF

SPRINT - last microwave contest of the season

I have attended the SPRINT contest from YMCA parking lot in EM48sq on Saturday, September 29, 2012. This was my last microwave activity of the season, for I have to make series of business trips for the rest of the year.

I have achieved one significant goal today - finally, after nearly a year of trying and trying, I have worked Zack W9SZ on 10GHz CW from his location in EN50rl, over 160 miles away. This is my grid #6 from my YMCA location. Thanks for all the patience, Zack!

More details about today's SLAMS club event are available here.

My station today

Terrain profile

Hepburn chart

Weather conditions

Vapor image

(I believe that this made the difference)

73 Herbert

AF4JF

ARRL VHF Contest

I have spent several hours making QSOs in the ARRL VHF Contest today. Chosen location for this was Winfield, MO in EM49 once again. I went there to test this new location on 23cm and for another attempt on 10GHz with Garth W0GR. There were several attempts made during last two weeks, see my other posting here. There even was a successful attempt earlier this week, described in my posting here.

EM49pa

I have heard Garth on 10368.1 MHz about S2-3 in the morning, right at the sunrise in my location. My dish antenna was pointing 5deg. up. Generally, Garth's signal was much weaker than during our last successful attempt earlier this week. Neither Garth nor myself have copied the WB9PNU/B beacon on 10GHz this morning. We didn't make full 2-way QSO today.

Pointing 270deg. towards W0GR

Garth didn't copy my signal on 10GHz this morning. However, we managed to work each other on 144MHz, 432MHz and 1296MHz with solid copy on each band. 

Eggbeater for 144 and Yagi for 1296 and 432MHz

I have also worked John WB9PNU from his home in EM48tm on 144, 432 and 1296MHz and Jim N5MU who was testing another promising portable location in St. Peters area, EM48qr on 144 and 1296MHz.

Pointing  432/1296MHz at John/Jim in EM48

Overall, a successful test, even without complete 10GHz QSO with W0GR. It's nearly 200 miles to his location and we managed full 2-way contact on 1296MHz, after all.

Included below are pictures from the nearby River Dam and Lock in Winfield.

I will certainly return to this beautiful location, either for more HAM QSOs or just to enjoy the view of the huge Mississippi River!

73 Herbert

AF4JF

ARRL VHF and SPRINT Microwave Contests

I will be QRV on 144-432-1296 and 10368 from EM49pa in the ARRL VHF Contest this coming Sunday 09/09 between 6:30am - approx. 10:00am.

Going to a series of business trips after that. However, I should be in St. Louis for last weekend of September.

I expect to attend SPRINT Microwave contest on Saturday 09/29 from EM48 and EM49 as a ROVER, using 1296 and 10368 only. My intention is to MOVE around EM49 in order to find good new location and also make at least one QSO from EM48 to qualify for the ROVER category.

That will be the end of my microwave activities this year. Not even a MAD activity until February. Might be able to attend SLAMS breakfast on Sunday, 12/02.

Looking forward for QSOs with you!

73 Herbert

AF4JF

MAD Activity on September 1st and 2nd

Update: Report from this MAD Activity (09/01 and 02)  here, more here.
--------

Next MAD Activity is planned for Saturday, September 1st.

I will be at YMCA in EM48sq. Planning to be ready for 10GHz at 6:00am. I might set up 1296MHz later in the morning, assuming there will be stations to work.

Will try to have 144.260MHz with me. Calls on my cellphone will be OK.

73 Herbert

ARRL "10GHz And Up" Contest 1/2 - Day 2

I have set up at YMCA in St. Louis (EM48sq) today. Main intention was to try work Zack W9SZ from EN50 and Ron from EM59. Weather was somewhat cloudy with little chance for Rain Scatter. It was raining a little when I arrived at the hill, so I have "installed" an "all-weather-option" on top of my 10GHz station:

First of all, I have heard Zack W9SZ when aimed my dish at an airplane departing from the Lambert St. Louis airport! He was S9 but this propagation didn't last long - that airplane was departing West, almost perpendicularly to the path between Zack and me. Tried again with next airplane, no luck. Maybe we should find a spot in the direction of main runway next time .. ?

Tried with Ron KO0Z later and heard him S9+. Ron was in EM59cm today, little bit North of his usual location, which gave me clear view in his direction from YMCA. However, he didn't hear me. Tried several times, then found a damaged transfer relay at my dish antenna .. the relay was switching (means clicking), but the "TX" path didn't connect. I have to check my sequencer before replacing the relay, which can't be done on hilltop, so this contest ended for me and I have returned home at 9:30am.

Before leaving YMCA, I have taken a picture of the view towards EM49pa from the garbage dumpster behind the building where N5MU worked me from on yesterday - it's actually very good spot for that direction!

73 Herbert

AF4JF

ARRL "10GHz And Up" Contest 1/2 - Day 1

I have set up in EM49pa near Winfield, MO, just off MO-79 and MO-N highways for the first day of this contest. The intention here was to find new location in EM49 closer to my house than the AT&T tower near Dow in IL where we usually go.

There were several promising locations above 700ft a.s.l. in the wooded area north of Foley, MO but there also was a problem - a bridge under repair between Foley and Winfield. Detour was huge, so I decided to set up in the lowlands (430ft.) close to the river for today.

I arrived just for sunrise, exactly as planned. Picture doesn't nearly capture how nice it looks!

Following two pictures show my 10GHz antenna and my 144MHz omnidirectional "eggbeater".

The higher ground on opposite side of the Mississippi River turned out to be a "little" problem - I didn't work anybody from that direction. However, there was nobody closer than ~100 miles, so it might not be caused by these hills after all (picture taken towards East).

Next picture shows the view in opposite direction (West). These hills sure aren't looking 300+ ft. higher than my location!

Anyway, after 4 hours of trying, I have only worked N5MU from EM48sq (27 miles) and WA0CNS from EM48rl (38 miles). These two QSOs proved that this location is good for QSOs with stations in St. Louis area and that was the main goal today. I will have to keep looking for more elevated spot in this area for long-range QSOs with stations located across the Mississippi River.