MICROSOURCE Synthesizer Issue

I have obtained two MICROSOURCE synthesizers some time ago. Label on that device says:

       FREQ:   10.2 - 13.35 GHz

I was told by several other HAMs that this unit is practically identical to ELCOM unit and can be controlled through a device with 12F675 processor, such as described by Dave WW2R here. The only difference is supposed to be the oscillator type - ELCOM uses "DRO" while MICROSOURCE uses "YIG".

I am not a beginner with ELCOM synthesizers. In fact, I already have a 24GHz transverter based on DFS1201, so I thought that using this new MICROSOURCE unit to generate signal for 24GHz beacon would be piece of cake. Well ...

The synthesizer simply refused to cooperate. I tried to program it for various frequencies above 12GHz, but it always generated 12GHz output signal (note that my counter isn't locked to GPS yet):

I spent hours researching Internet and checking my wiring, switching synthesizers .. nothing. I even contacted Dave WW2R by email, but he didn't have "hands-on" experience with this model. After quite some time I finally remembered that Michal OK1VM published something about this synthesizer on his web site, so I have sent him an email.

OK1VM told me that he has some recent experience with this synthesizer. He also mentioned that although the label on the MICROSOURCE unit says otherwise, it ONLY responds to programmed frequencies in the 11.2 - 12.0 GHz range. So, I have modified my programming to 11.88GHz and here was the result:

OK, the synthesizer works. I can't use it for a small 24GHz beacon, but there are many other ways how to utilize these wonderful devices. 

Again, no matter what the label says, both of my MICROCOM units let me set them to a frequency in the 11.2 - 12.0 GHz range ONLY, exactly as DFS1201 from ELCOM.

So, before you decide to buy such a unit (mine came from eBay), be aware that your synthesizer might have the same limitation as mine does.

Thanks to Dave WW2R and Michal OK1VM for their help with solving this mystery!

73 Herbert

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.

ARRL "10GHz And Up" Contest 1/2

First leg of the ARRL 10GHz Contest will take place next weekend, August 18-19, see rules here.

I intend to set up for 10GHz in EM49pa just North of Winfield, MO on Saturday August 18 in the morning.

I will set up at YMCA in Maryland Heights, MO, EM48sq on Sunday August 19 in the morning.

Call me on 144.260MHz to try 10GHz contact.

73 Herbert

AF4JF

ARRL UHF Contest

I have decided to attend the ARRL UHF Contest on August 4-5, 2012. However, my own body didn't accept my own mind's decision and went on agenda of its own - I have developed a bad case of virus-based summer illness. Thanks to that, my Saturday plans went to the range of SCI-FI (I have planned to install my 55el. 23cm looper on my house) and I have spent the day mostly in bed.

Sunday didn't start bad. I was able to wake up pretty early and get to my usual hilltop at YMCA in EM48sq. I have packed everything up, checked Rain Scatter conditions, read last email from Zack W9SZ who agreed to continue in our usual game of trying for 10GHz QSO between EN50rl and EM48sq and went to the hilltop.

This was the first time for my new 70cm Cushcraft antenna and new cable for my 23cm Comet. The "LMR400" cable with "N" connectors replaced my old "RG213" with "UHF" connectors which is used to feed my new 70cm antenna now. See following pictures:

Everything actually looked pretty good, except of the mess on the little folding table. This is mostly for my 35W PA for 1296MHz which needs 24V. I didn't have time to make new wiring for second 12V battery, so the only option for today was a power inverter and switched power supply for the PA. I promise to finish all that until next contest.

I have flipped the switch and immediately got hit with a booming sound - N2BJ from EN61 was "full scale" (that's a gross understatement) along with several other stations on 432MHz SSB/CW. I have worked some when Jim N5MU arrived. He worked some of them too. I have originally intended to use the 70cm radio only to contact Zack W9SZ before trying for 10GHz, so I didn't bother to bring a PA. I have only run 432MHz with 5W from my FT817 IF radio today.

W9ZIH was skeptic about trying for 23cm, so I didn't ask for it. However, his 70cm signal kept growing and when he agreed to try 1296MHz with WB9PNU, I have "cut in" and called him first. Perfect QSO, my first with W9ZIH on 23cm CW! We kept listening to Ron and I have asked to try on 10GHz when other stations stopped calling him.

I have copied W9ZIH on 10368.101 MHz immediately, but weak. Discovered quickly that his signal is coming from "above", but aiming my dish 15degrees up fixed that. I also discovered that it is coming right through a nearby tree:

It took about 20 minutes to complete the 10GHz QSO, but it is done. My grid #5 for VUCC on 10GHz from this location!

Ron played the 10GHz WB9PNU/B beacon back to us on 70cm, full S9 at his place, 237 miles away! We have called other SLAMS members to try, but when Ron KO0Z tried 23cm with Ron W9ZIH, the good propagation was gone, so they never got to trying 10GHz.

I haven't heard from Zack, W9SZ before I left the hill. Called Ron KO0Z from home once more and learned that Zack was on the air with him, but I was at home already. Well, we will make our 10GHz contact next time, some other day ...

I have also worked Ron KO0Z on 220MHz from home, but that's another story.

73 Herbert

Possible Microwave Locations

We have taken a friend from Germany on a short "winery trip" last Sunday. Attached pictures show possible microwave locations that we have discovered along our way. They are all in EM48. First picture is from Hermann, MO viewing West, remaining two are from Grafton, IL viewing South-West and North-West. Wine was excellent.

PTT output for IC251a

Friend of mine (Rich, N0PQU) owns IC251a. It is a nice reliable 144MHz all mode transceiver. Rich wants to use it as IF radio for his 10GHz transverter. Problem is that this radio doesn't have PTT output.

We have found nice article (by Scott N0EDV) about installing a sequencer inside this transceiver. However, his technical solution wasn't exactly what we needed, so we designed one of our own.

The IC251a has a RX-TX switch on its front panel. Our first idea was to use that. This switch has +9V on it in RX mode and 0V in TX .. apparently the 9V comes from a switching logic inside the radio and the RX-TX switch grounds that when transmitting. 

We needed something with high impedance and we also needed the logic reversed (switch relay in TX mode), so we designed following circuit:

First half of the OP-AMP, the "O1a", is basically a "unity gain amplifier" with very high input impedance and  the second half, the "O1b", is a voltage comparator. Should the input voltage on the PTT switch drop below ~8V (RX-TX is switched), then the comparator energizes its output, "LED1" comes ON and the optical insulator "OP1" switches its (galvanically isolated) output ON. Exactly what we needed.

HOWEVER

Connection between "PTT" input and the RX-TX switch must be made with a 100k resistor in series, otherwise the "unity gain" amplifier doesn't copy the "0" voltage when switched to TX. This is because of the way how this OP-AMP is connected to the power supply - no negative voltage applied. In the real world, the "-" (inverting) input always has a little lower voltage than the "+" (non-inverting) input, so if you ground the "+" input by PTT directly, the "-" input has nowhere to go and "O1a" goes to output >10V.

We have taken several pictures of the connection points inside the radio to share the idea:

Everything works well on a test bench. We will connect it to the transverter soon and update this Posting with results of that.

UPDATE 

This radio was successfully used for 10GHz contacts on 09/29/2012, details here.

23 cm Beacon for St. Louis

I have returned to my delayed project of a 23cm beacon for St. Louis. It will be running 10W to 4x "wheel" antenna (by WA5VJB) on 1296.350 MHz and will be located in EM48ss next to the WB9PNU beacon for 3cm.

Here is a picture of the oscillator unit in a small box. The circuit board (by W6PQL) has an oscillator on one side and temperature-controlled oven on the other. This small box will be enclosed in Styrofoam inside bigger box:

Some pictures of the antenna:

I will update this posting with more details and pictures as soon as I have something new to share. It might take some time, but the goal here is to have the beacon operational by the end of this year (2012).

MAD activity on a Hot 100F Day 07/07

We have tried to participate on MAD (stands for "Microwave Activity Day") activity today.
I have met with Jim N5MU at the YMCA parking lot in EM48sq again. Today's goals were:

• work W9SZ on 10GHz in EN50rl ... didn't happen
• work NG9R on 144/1296MHz in EN40na .. achieved
• test "Eggbeater" antenna on 144MHz liaison frequency SSB ... worked well
• test my "new" 30W/1296MHz amplifier ... worked very well

Would you believe that it takes almost half an hour to set up all this equipment?

AF4JF equipment for 144/1296/10368MHz used today

I have obtained a 23cm PA from KM5PO (on eBay) long time ago. It works very well, but requires 24V for the power FET and 16V for transfer relay. I have used a power inverter to generate these voltages from my 12V battery.

The 23cm PA, SBMS concept with Infineon PTF10021 FET, is the box with huge heatsink in the middle. The gray diecast box on its left is my 23cm DEMI transverter. Power inverter is on its right. You can also see two power supplies (24V and 16V) in the front of the picture, next the the Diamond SWR meter:

AF4JF gear

Detail on the 23cm PA and the MFJ Power Booster

12V Deep Cycle Marine Battery

(see Power Poles for the Booster and Clamps for Power Inverter)

Overall, a successful day. I will try to consolidate all that 23cm gear into one nice compact box with one power connector. Well, maybe two, but not 4 ... Some day.

73 de AF4JF

EM48sq

Power Supply for DMC modules 24GHz

DMC modules used for 24GHz transverter (see my other post here) need (+8.4V) and (-5.0V) voltages, where the (-5V) must be applied first.

I have built a simple power supply that honors this requirement. Original idea came from another HAM's web site. I liked this simple solution with a Zenner Diode, so I adapted it for my needs:

First test results were good. Note that output voltage (+8.4V) can be adjusted by changing resistance of R3. In my case, I have used two resistors in parallel. PCB provides enough space for both of them.