Problems at 105.5W?

[ncjay]

Has anyone noticed a severe attenuation, or even disappearance, of the signals from UFO6 at 105.5W within the last week or so? Its close neighbor, UFO5 at 99.4W is as strong as ever.

I happened to find an SDR# screencap from October 27, and just now made a matching one of the same slice of spectrum - they're attached. Using Matt Blaze's excellent listing, those eight strong transponders from 243.915 MHz to 243.985 MHz on both screencaps are listed as being on 99.4W. You can also see faint signals from UFO7 at 21.9W from 244.075 to 244.145 on both screencaps (the view of that satellite from the antenna position is blocked by woods to the east). And on the first, October 27 screencap only, the eight strong transponders from 244.155 to 244.225 are in evidence. They're extremely faint, or perhaps even gone, on today's screencap.

Nothing in Matt's list that's listed as being on 105.5W is audible or visible in SDR# for the last week, sadly including Radio Cajamarca Viva, the enjoyable Peruvian station normally heard loudly on the low side of the 268.450 transponder....

nc-jay
Wake Forest NC

[blaze]

Thanks for the update.

Yep - I can confirm. All the UFO6 transponders seem to have gone quiet, including narrowband data, voice, and the fleet broadcast on 250.650

Time will tell if this is temporary or permanent. All these sats are near or past the end of their original intended service life.

I'll update the web page if it stays that way for a week or two.

[mancow]

I noticed the continuous chatter of the pirares has definitely been reduced.

[brandon]

Seems to be similar to what happened last year
http://forums.radioreference.com/spa...n-just-me.html

[blaze]

As of today (9 November 2012), some - but not all - UHF6 transponders appear to be back on the air. In particular, all the 6 KHz data transponders at 244 and 249 MHz seem to be back, as are all the 30 KHz voice transponders except for 250.650, 253.850, 255.550, 267.050, 268.450 and 269.950.

However, the mystery Pacific satellite which shared some of the (bandplan Quebec) UFO6 transponder frequencies now appears to be completely off the air.

[ncjay]

Now 268.450 is back, and along with it, Radio Cajamarca Viva. I could listen to this all day!

Will do a more comprehensive survey tomorrow when I can put the Trivec back outside.

[KR0SIV]

ncjay
What hardware (other than the sdr) are you using for RX?
antenna, pre-amp, etc?

[ncjay]

Antenna: Trivec Avant AV2040-1
Pre-amp: RF Bay LNA-300

ncjay

[KR0SIV]

thanks, I'll look into that.
Holy crap by the way on that antenna price!

[blaze]

Originally Posted by KR0SIV

thanks, I'll look into that.
Holy crap by the way on that antenna price!

Don't be too put off by the prices on ebay.

The used prices on these antennas vary widely, especially on ebay. You should be able to pick up a good working 2040 or 2055 antenna for less than $150 if you shop carefully.

[KR0SIV]

Thanks blaze, I'll keep looking.

I'd love to get one, or two of these guys

[nmelfi]

This is a little off topic,but while we are talking about antennas,has anyone tried this before? I have a 12 foot satelitte dish that I can aim at 105west and I built a ground plane 250meg antenna,if i place the antenna at the focal point of the dish would this work as a yagi to recieve milsat?

[prcguy]

Use a dipole cut for about 255MHz at the focal point and it will work just fine. There will be around 3dB loss from using a linear pol antenna receiving the circular pol downlink but the added gain of the 12ft reflector will more than make up for it.
prcguy

Originally Posted by nmelfi

This is a little off topic,but while we are talking about antennas,has anyone tried this before? I have a 12 foot satelitte dish that I can aim at 105west and I built a ground plane 250meg antenna,if i place the antenna at the focal point of the dish would this work as a yagi to recieve milsat?

[blaze]

Originally Posted by prcguy

Use a dipole cut for about 255MHz at the focal point and it will work just fine. There will be around 3dB loss from using a linear pol antenna receiving the circular pol downlink but the added gain of the 12ft reflector will more than make up for it.
prcguy

Agree - dipole is definitely the better driven element here (compared w/ a ground plane).

[nmelfi]

But a dipole would not be in the focal point of the dish?Maybe just a element cut to the correct size in the center of a so 239 and a earth ground to the base of the connector.

[blaze]

Originally Posted by nmelfi

But a dipole would not be in the focal point of the dish?Maybe just a element cut to the correct size in the center of a so 239 and a earth ground to the base of the connector.

With a 12 foot dish, a dipole at the approximate focal point (oriented parallel to the dish) should be fine. If you have a clear shot to 105W the gain of a dipole alone should give you a sufficient signal level The dish will mainly help reject terrestrial interference.

[nmelfi]

Sounds like I have a project next weekend, Thanks guys.

[nmelfi]

I just ordered a center conductor to build a dipole. Stay tuned next week for results.