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

HAM Weather

I hope this was last snow of the winter season. That tree blessed our roof with its touch at 2am ("nice" wake up), but surprisingly did only little damage, mostly to the old TV dish that was used for NASA TV only. Well, it was my backup for 24GHz :(

Part of the tree still on the roof

That dish lost its geometry somehow

At least my other antennas survived ...

... as did my bigger dish

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