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 41 
 on: Today at 01:44:45 PM 
Started by KD0ZGW - Last post by KG4RUL
Keep in mind that trees and branches move in high wind conditions - not always in the same direction.  You will either need to provide slack in the messenger cable or provide some strain relief.  I have used this product on wire antennas: http://antennatensioner.com/drupal/ with good success.  During hurricane Matthew, a branch broke off higher up in the tree and fell onto the antenna wire and got hooked on to it.  When I was finally able to remove the branch, the antenna was undamaged.

 42 
 on: Today at 01:37:22 PM 
Started by KH6AQ - Last post by K0UA
Tim, yes it was just a bit over an hour until sunset. 40 meter is the band out here and it's open to the mainland from 0250 until 1400Z. I'm running 500 watts to a vertical.

Do you ever work 80 meters digital?

I really need an HI station on 80 meters to finish out the 80 meter portion of 5 band WAS, and of course HI is the only digital contact state I don't have on 80.  I have stayed up many a sleepless night looking, but have never found one of you guys on 80.

 43 
 on: Today at 01:33:19 PM 
Started by WA2ISE - Last post by WA2ISE
Heard that nuke bombs can produce electromagnitic pulses(?) that can fry the front ends of radios.  I don't know if this is just an urban legend, or if it's a real problem (assuming N Korea actually launches an H bomb and blows it up over the Pacific, as they mentioned thinking of doing...).  Many other problems this would cause would be far more serious, like all that radioactive crap let loose in the air.  Power companies might not handle it well, either.  (I'm talking about places far enough away that are not vaporized by a direct hit).  Cars' electronics might not like it either.  Even if you kept an old 2m HT stashed away in a metal sealed box, you couldn't charge its batteries if the power company and your car are dead...  

I doubt that NK would actually do it,  Huh  



Maybe make sure your tinfoil hats are well grounded.   Grin  

 44 
 on: Today at 01:33:07 PM 
Started by N2EY - Last post by N9KX
I'm not sure I understand this thread.  Why or who cares about FCC license Counts?  Jim you keep putting up the stats and stuff but I'm not sure why.  What am I missing?       

i cant speak for Jim, but this thread certainly lays to rest the idea that Ham Radio is dying or dwindling.  (graphically it is an incline) 73  Wink

 45 
 on: Today at 01:33:02 PM 
Started by KK4OZH - Last post by W8KFJ
Disclaimer - I am a direct-sampling SDR nut.  It is today's radio, not yesterday's.  Start your research on my QRZ page, but that is only the beginning.  I particularly like the Elad FDM-DUO.

Dave  W8KFJ

 46 
 on: Today at 01:29:22 PM 
Started by KF5YTK - Last post by K0UA
My question is to those that own this rig, have you upgraded to another microphone and what is your recommendation for settings on the particular mic you paired with it? 

I purchased this rig and also purchased a Heil pro 7 headset and was curious if anyone else had done the same ! Thanks and 73's

I haven't upgraded.  I use the rig mostly portable and the reports of audio quality have been good with the supplied mic.  I use compression, but turned down the default setting. If I used it mostly in the house, I would have a headset too.

 47 
 on: Today at 01:24:39 PM 
Started by KG4ABA - Last post by K7KBN
... and locate the line, 10 gage  Rolex.

Even a Casio would work.

 48 
 on: Today at 01:21:58 PM 
Started by KC2NLT - Last post by K0UA
Just thought I would add my experience to what is a very relevant topic.  If you go way back to the tube days, most receivers had pre-selectors.  That was an extra tuning step though, and soon receivers started to sprout band-pass filters for the ham bands.  This worked well unless you wanted to get rid of a 40 meter CW station, while you were on 40 SSB.  Nevertheless, these filters became the norm for the later years of the superhet era.  If you wanted to listen to anything but the ham bands though, you had to either add more filters, or bypass the existing ones.

Enter the SDR era, and confusion abounds.  Not all SDRs are equal.  The direct-CONVERSION type (Flex pre-6000 series, and many others) are only somewhat better than superhets.  The more conversion stages, the worse the intermod products, and the triple-conversion superhet was the worst.  I think it was Yaesu that touted its newer double-conversion radio over its older triple-conversion superhet.  The problem was that ONE conversion stage still existed in even the best SDRs of the day.  Can we get rid of that last remaining conversion stage?

The answer is a resounding YES!  In 2012, Flex-Radio introduced the 6000 (direct-sampling) series with the 6500 and 6700.  Also in 2012, but with less hoopla, Apache Labs in India, introduced the direct-sampling Anan 10, based on the open-source Hermes board developed by the Open HPSDR group, and manufactured by Apache Labs.  These radios didn't just digitize a couple-hundred KILOhertz of the spectrum by using a VFO to down-convert that narrow spectrum, they digitized the whole thing!  By sampling above 60 MEGAhertz, they could digitize everything through ten meters.  Double that to 120 MEGAhertz, and six meters was included.  As Flex touted, this was indeed a game-changer!  With good design, intermod products were practically eliminated.  Radios could now be made WITHOUT pre-selector filters for all but the most demanding situations.

I had already purchased a Flex 3000, but I became intrigued with this direct-sampling stuff, and by December, 2013, I bought a Hermes board.  This was a complete receiver, and half-watt transmitter.  There was no enclosure, and certainly no front-end band-pass filters.  When it arrived, my excitement prevailed.  I loaded the HPSDR software, connected everything and threw the big switch.  Light lit, there was no smoke, and the receiver worked VERY well.  But what could I do to test the improved intermod situation promised by direct-sampling?

I remembered quite a few intermod products appearing in the lower part of the AM broadcast band on the Flex 3k.  They were not there in the Hermes!  Let's try WWVB on 60 KHz.  The Flex 3k had so much intermod from AM broadcast, it was useless.  The Hermes was perfect, as is my Elad FDM-DUO.  I live in the greater Cleveland area, so there are many STRONG AM stations.  A friend, who lives in the boonies, tried his Flex 3k on 60 Khz, and it was fine.  Bottom line – filters are only needed in the most extreme cases!

The good news – prices of the high-speed A/Ds and FPGAs needed for direct-sampling are plummeting!  The ColibriNANO, Elad S1, and KiwiSDR direct-sampling receivers can be had for around $300.  The KiwiSDR is particularly interesting, as it includes a Beaglebone computer and GPS oscillator steering for $300.  It is designed to be used over the internet by up to four simultaneous users.  Although these receivers are14 bit, direct-sampling allows over-sampling techniques to obtain bit depths of 24 – or better.

I will never buy anything but a direct-sampling radio!

Dave   W8KFJ



Dave, thank you for that comprehensive, yet easy to understand synopsis on SDR.   73 James K0UA

 49 
 on: Today at 01:08:49 PM 
Started by KG4ABA - Last post by KM4AH
I think it is NFPA, but same difference.

 50 
 on: Today at 01:07:20 PM 
Started by N4OI - Last post by KB1WSY
Speaking of "Titanic," I always thought that SOS was "Save Our Souls" but it turns out to have been originally a German code adopted internationally in 1905. I also did not know that it is a prosign, and is thought to be distinctive in part because it has nine elements whereas supposedly no other prosign has more than eight elements. (All the above from Wikipedia.)



1913 Marconi operator room for 5 kilowatt ocean liner station (public domain photo).

73 de Martin, KB1WSY

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