[MAMS] April 2011 Microwave Activity Day

Mon Apr 4 17:39:20 EDT 2011

Surprisingly, my dish wasn't damaged, even after it literally flew
over my car WITH the tripod at one point. I did get a scratch in the
car.

My IF rig was damaged when the table blew over. I don't think a radome
would've kept either the radio or the dish from blowing over.

Next time I won't bother to try to set up if the wind is that
ferocious. I suppose I could've carried some sand bags for weight but
there's only so much you can fit into a Toyota Corolla!
:-)

Zack W9SZ

On Mon, Apr 4, 2011 at 3:36 PM, Dr. Gerald N. Johnson
<geraldj at weather.net> wrote:
> Yes, the wind got you at least twice by destroying propagation and
> equipment. I don't know that a portable radome would have helped the
> propagation but it should have saved the equipment.
>
> 73, Jerry, K0CQ
>
> On 4/4/2011 3:33 PM, Zack Widup wrote:
>> In my case on Saturday, it was a hindrance to microwave antennas,
>> equipment and operating! I couldn't even keep the dish up long enough
>> to aim it at anything.
>> :-)
>>
>> 73, Zack W9SZ
>>
>>
>> On Mon, Apr 4, 2011 at 3:29 PM, Dr. Gerald N. Johnson
>> <geraldj at weather.net>  wrote:
>>> Wind is often a significant hinderance to VHF and microwave propagation.
>>> Without wind and clouds, night radiant cooling of the earth's surface
>>> cools air near the surface causing a temperature inversion that enhances
>>> refraction. Evaporative cooling over water bodies gives much the same
>>> effect. In the prairie typically that morning inversion is about 1000
>>> feet above the ground. Often visible when flying up in a small airplane
>>> or observing a smoke or steam plume from a fire or power plant. Wind
>>> stirs the boundary layer and destroys the inversion by mixing. Gusts are
>>> better at mixing. Cloud cover over land holds in heat and so tends to
>>> prevent the little inversion forming.
>>>
>>> A high pressure dome has no wind under it and that inversion can build
>>> and isn't destroyed and can build up over days to cover a large area
>>> with propagation out to 1500 miles or better.
>>>
>>> We work beyond line of sight with normal conditions because of the
>>> atmosphere is less dense with altitude and that gradient of density
>>> causes some refraction, the 4/3 earth radius rule.
>>>
>>> 73, Jerry, K0CQ
>>>
>>> On 4/4/2011 10:31 AM, Zack Widup wrote:
>>>> Conditions on Saturday were evidently very poor. I cannot verify that
>>>> I was NOT putting out power on 902 MHz, so I am going to assume I
>>>> actually was when I tried to work Wally W9OBG. When I got everything
>>>> home and checked it out, it appeared the only damage to the IF rig
>>>> from a fall onto the ground was a damaged squelch control knob/shaft,
>>>> and everything else was working normally. I was getting 10 watts out
>>>> of the 902 MHz transverter as expected. Since Wally was running 200
>>>> watts or more and I was only getting him S9, and he couldn't hear my
>>>> 10 watts at all, I am now assuming conditions were that bad. Lloyd
>>>> NE8I has said that condx were really poor up in Michigan where he was.
>>>>
>>>> I can get to the hilltop in EN50rl just about any morning of the week
>>>> between maybe 6:30 and 8 AM CDT. as well as some hours during most
>>>> weekends. If the Hepburn forecast looks good and if anyone wants to
>>>> try to work me, let me know. I just hope it isn't a windy day!
>>>>
>>>> I haven't attempted an SDR radio for a microwave IF. It might be a
>>>> good idea as you could see a good chunk of the spectrum all at once,
>>>> and when you've identified a signal all you have to do is peak your
>>>> dish on it. But there is so little time and I'm spending a lot of time
>>>> trying to get my 24 GHz transverter going. I just made a few boards
>>>> that are basically the W1GHZ Miniverter-F but the helical filters for
>>>> 432 that I have are smaller than the ones he is using (hence I made my
>>>> own boards with my filter size specs rather than order some from him).
>>>> I want to use this as a 432 MHz IF for the 24 GHz SDH transceiver I
>>>> have. I'm also working on putting together the LO chain to give me 6
>>>> or 7 dBm at 11.800 GHz. I might get that done this week.
>>>>
>>>> Then I'll start thinking about 47 GHz.
>>>> :-]
>>>>
>>>> 73, Zack W9SZ
>>>>
>>>>
>>>> On Mon, Apr 4, 2011 at 9:56 AM, M Ragouzis<n0obi at yahoo.com>    wrote:
>>>>> Hi Dave
>>>>>
>>>>> Thanks for the note of the 11th.
>>>>>
>>>>> My brother  Bruce ,  may have a 6 foot fiberglass dish to give away , he spoke
>>>>> about it yesterday and he lives near you.
>>>>> I have a phone call in to his message center now just so he doesn't cut it up
>>>>> before some one has a chance at it.
>>>>>
>>>>> I hope things are going well for you , we should have a breakfast meeting some
>>>>> time , what do you think ? , I do not know anyone in the club by face ( how many
>>>>> are here in the st louis area ) .
>>>>>
>>>>> Is anyone working on SDR using the Apple i-phone or i-Pod products for  a 10
>>>>> ghzreceiver ?
>>>>>
>>>>> I'm still working on getting the SDR radio up and running , I found a 741 OP amp
>>>>> in the junk drawer last night , the RF front end will work through the computer
>>>>> sound card but not through Jim's i-phone or i-pod , so it looks like the i stuff
>>>>> needs more gain , Jim discovered ad added the 10M ohm resistor across the mic
>>>>> input to let the i-phone/pod know that it has and external mic.
>>>>>
>>>>> Plugging in the mic/sdrrffront end caused a spike to form on the display but
>>>>> nothing more than this , were getting closer.
>>>>> I don't know that the 741 will be quiet enough , but as things are right now
>>>>> something would be better than nothing.
>>>>>
>>>>> If we go through the 1/8 inch jack we only get one channel so it I or Q and we
>>>>> have just a one channel direct conversion radio ( ? ).
>>>>> But we will have the ability to use the software to narrow down the band width ,
>>>>> so this should be real good for 10 ghz.
>>>>>
>>>>> I have the 2 meter N-channel amp built , I just need to tune it up .as you know
>>>>> we were talking about dynamic range problem's , I hope this and sdr will make a
>>>>> running receiver.
>>>>>
>>>>> OH , I picked up a "Gunn Oscillator " that I tuned to 10.368 ghz , so it might
>>>>> be good for CW even though its a little wide  ( I have a filter ) .
>>>>>
>>>>> So much stuff to do so little time.
>>>>> Mike
>>>>> N0obi
>>>>> 73
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> ________________________________
>>>>> From: Dave Calvert<kb0pe at yahoo.com>
>>>>> To: Mid-America Microwave Society<mams at mailman.qth.net>
>>>>> Sent: Sat, April 2, 2011 9:28:53 PM
>>>>> Subject: [MAMS]  April 2011 Microwave Activity Day
>>>>>
>>>>> I went to EM49au ( AT&T microwave tower site ) and setup at 6am and was ready to
>>>>>
>>>>>
>>>>> go on 902, 3456 and 5760....  It was windy and the bands were dead!  I looked
>>>>> around
>>>>> for the beacon on 902 (K3SIW's) and nothing.  I did have some long q's on
>>>>> 144.200
>>>>> at around 11am with South St. Louis and that was it....
>>>>> 73,
>>>>> Dave -KB0PE
>>>>>
>>>>> Starting Monday April 11th, 7-11PM local. 2M Sprint.
>>>>> Tuesday April 19th - 222 Sprint.
>>>>> Wednesday April 27th - 432 Sprint.
>>>>>
>>>>>
>>>>> ______________________________________________________________
>>>>>
>>>>>
>>>>>
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