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From Gil's Shack (N2GG)
A Treasured Member of Group 7155 Sends us his Articles
1 - NVIS Antenna
2 - Myth of Reflected Power
3 - How the Internet Got Started
4 - ICOM 7610 Observations


Subject: Superior 7' high, High Gain, 40 meter NVIS antenna

Here is a superior design for the 40m NVIS antenna I talked about a few months ago.  It's relayed from Bill, K7ZM.  He lives in an antenna restricted housing development in Los Lunas, about 6 miles north of me.


Subject: The Myth of Reflected Power

Thanks to Tim, KX7P, for this relay.  This is probably more SWR information then many hams want to know, but, it's well written and worth digesting.


How the Internet Got Started - According to the Bible
Please do not Google or check this with Snopes.  They will lie to you.  Trust me!
In ancient Israel, it came to pass that a trader by the name of Abraham Com did take unto himself a healthy young wife by the name of Dorothy.   And Dot Com was a comely woman, large of breast, broad of shoulder and long of leg.  Indeed, she was often called Amazon Dot Com.
And she said unto Abraham, her husband, "Why dost thou travel so far from town to town with thy goods when thou canst trade without ever leaving thy tent?"
And Abraham did look at her as though she were several saddle bags short of a camel load, but simply said, "How, dear?"
And Dot replied, "I will place drums in all the towns and drums in between to send messages saying what you have for sale, and they will reply telling you who hath the best price. The sale can be made on the drums and delivery made by Uriah's Pony Stable (UPS)."
Abraham thought long and decided he would let Dot have her way with the drums.  And the drums rang out and were an immediate success.  Abraham sold all the goods he had at the top price, without ever having to move from his tent.
To prevent neighboring countries from overhearing what the drums were saying, Dot devised a system that only she and the drummers knew  It was known as Must Send Drum Over Sound (MSDOS), and she also developed a language to transmit ideas and pictures - Hebrew to the People (HTTP).
And the young men did take to Dot Com's trading as doth the greedy horsefly take to camel dung.  They were called Nomadic Ecclesiastical Rich Dominican Sybarites, or NERDS  And lo, the land was so feverish with joy at the new riches and the deafening sound of drums that no one noticed that the real riches were going to that enterprising drum dealer, Brother William of Gates, who bought off every drum maker in the land. Indeed he did insist on drums to be made that would work only with Brother Gates' drum heads and drumsticks.
And Dot did say, "Oh, Abraham, what we have started is being taken over by others." And Abraham looked out over the Bay of Ezekiel, or eBay as it came to be known.  He said, "We need a name that reflects what we are."
And Dot replied, "Young Ambitious Hebrew Owner Operators."  "YAHOO," said Abraham. And because it was Dot's idea, they named it YAHOO Dot Com.
Abraham's cousin, Joshua, being the young Gregarious Energetic Educated Kid (GEEK) that he was, soon started using Dot's drums to locate things around the countryside.
It soon became known as God's Own Official Guide to Locating Everything (GOOGLE).
That is how it all began. And that's the truth.
I would not make up this stuff.

From Mac to Gil Re: My Icom 7610

Hi, Gil,

One ham in US asked me about IC7610, I wrote my impressions, etc. I
thought you might be interested in it, too. Here is the copy and paste
of the email.

Although Icom became as big as one with more than 1,000 employees, JA3FA
was the senior engineer until IC7850/7851. Since he knew that he was
getting old, he decided not to make comments for a new model, which was
IC7300, Icom's first SDR radio. I asked him how he liked the radio at
Tokyo Ham Fair where they introduced IC7300 for the first time. His
answer was "I have never touched it yet". He was so nervous and kept
watching how people react to the radio at some meters away from the
booth almost all day long although he normally stayed there just for a
few hours in the morning. I am sure he was happy and relieved as it
became a very successful radio.

IC7300 is a very good radio, especially for its price, but the dynamic
range was a problem if you have a local ham or a commercial radio
stations very close to you.

When I received a new radio, I ask my local station who lives only
500-foot away from my QTH to come on 15m with his beam toward me and
with full power, which is about double of JA's legal limit. I did the
same when IC7610 arrived at my station. With his antenna beaming to me,
the whole band was dead, but when his 3-element yagi was turned to the
back, I could listen to a station 50kHz away although there were some
interference. I thought I could give "OK" to the dynamic range of IC7610
with this result.

I heard a very weak SSB signal on 40m with my IC7850. It was too weak to
move the S-meter at all. I switched to IC7610 right away with the same
antenna and same audio & speaker system. Amazingly, IC7610 had a more
clear readability than that of IC7850, maybe because of the lower
internal noise of the receiver. Probably it was caused by the conversion
noise of IC7850 which modulated the receiving signal.

When two very strong OHR signals, +20 to 30dB over S9, came around 6950
and 7170kHz simultaneously IC7610 started blinking its Overflow
indicator although I saw no interruption of the receiving. By turning on
"IP+" did not help much, but the DIGI-SEL stopped the OF blink. At that
time, I compared with IC7850 and found that the level of the receiving
SSB signal was the same in two radios, but when the voice stops the
S-meter of IC7850 dropped to S3 or so and that of IC7610 stayed around
S7. Some kind of over-flow was happening in IC7610 at that time, I
believe. By turning on the attenuator by 6dB, this problem was cured
and worked as well as IC7850.

Another thing I noticed with IC7610 is the filter. The DSP filter must
be designed the same as that of IC7850, but IC7610 has no roofing
filters. It makes the skirt characteristic of the IC7610 filter not as
good as that of IC7850 for sure. This could be improved by re-designing
the DSP filter for a radio without roofing filters.

The monitor scope seems to be slightly faster than that of IC7850 and
touch screen feature gives us easier usage of the radio although we need
a time to get used to.

After trying IC7610 for a couple of weeks, I feel that it is a good
radio for the price and I feel IC7610, of which the price is around
$3,000, is much better than other conventional radios in the same price
ranges, maybe better than even more expensive ones, too.

The internal speaker of IC7610 sounds fantastic, the best in all the
internal speakers I have tried. This radio could be a best sound AM
radio. This may be the reason why this radio weighs more than it looks.

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