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The mission of the Upper Rio FM Society, Inc. is to provide a State-of-the-Art Amateur Radio repeater network for the benefit of our members, licensed Amateur Radio operators, the community and provide public service communication support in times of emergency.
The Upper Rio FM Society
April 2018 News Letter

 

Next Membership Meeting is Tuesday, April 10th


Time – 6:30 PM (1830) Local
 
Place – At the Fellowship Hall of the Immanuel Presbyterian Church located at 114 Carlisle Blvd., SE, in Albuquerque. Please enter the church from the northern most entrance. DO NOT park in the Nob Hill parking lot to the west of the church, as police have been ticketing.
 
Program - The URFMSI is very pleased to have a presentation by Mike Langner, K5MGR on the Emergency Alert System (EAS). The EAS communications are an important link during  emergencies. Given the high fire danger this year, the presentation is very timely.

We also want to thank Bryan Burns, WA5VAH,  for his presentation at the last general meeting on the low cost mini Vector Network Analyzer (VNA). If you missed the meeting Bryan's slides are posted on the web site under Activities / Meetings / Presentations.

Resistors, Capacitors, Inductors - Oh My!

Upper Rio Vice President Don wood - W5FHA - has donated a large - no huge - amount of electronic parts to  the club.  These parts are available to club members upon request.  There are wall warts, resistors, capacitors, sockets, transformers, ferrite cores, copper clad sheets, over 1600 different semiconductors, zener diodes and much more.  To get these parts just send your parts list to Don Wood at W5FHA@arrl.net.  He will pull what is there and contact you - be sure to give your phone number.



Member Contributions

We are always looking for newsletter content. If you have something you would like to share please forward tha material to the newsletter editor at k5atm@arrl.net

This was forwarded by Mike Langner, K5MGR, and is a post from the Repeater-Builder Yahoo group.


From: Repeater-Builder@yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com]
Sent: Tuesday, January 23, 2018 1:07 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] LMR240 and Noise - Tested


Folks,

I know there has been a lot of discussion in the past about not using LMR type cable for full duplex use.
I had to put this to the test on the bench to see if this is a measurable / quantifiable thing. Sure enough, it does induce a lot of noise.

Test setup (hopefully my ASCII Art comes through ok ):



                            Dummy
                            Load
                              |
                              |  
 ------        Tee       -----|----          ------
| RX   |--------==------|Duplexer  |--------|  TX  |
 ------          |       ----------          ------
                 |                                 
           ------|-----
           | Service  |
           | Monitor  |
           ------------


The ISO Tee is used to inject the RX frequency and 1KHz tone for the 12 dB SINAD test. This has a 20dB attenuation; this gives me some isolation from the 50Ohm impedance of my RX cable and still allows me to generate a test signal to get a base line measurement.

Without the TX enabled, we take a measurement to use as the control dBm value without any desense.

Then with the transmitter on, I took another measurement to see if we lost any sensitivity. Well, it wasn't too bad, maybe 1dBm, if that.

But, if I moved the feedline to the dummy load (which was LMR240), oh my, lots of noise. If you vibrated the cable around, you'd get so much noise that I couldn't even measure the SINAD value any longer...

This was ONLY occurring when the Transmitter was enabled. For simplex...TX turned off, no issues what's so ever. I could drag the feedlin! e across the carpet...no issues with RX only. It was ONLY when the Transmitter was enabled that I could induce the noise while moving the cable around.

So I can clearly see why you'd not want to use LMR cable for the feedline to the antenna. Any wind and shifting around will cause noise.

But what is very interesting from this test, is that I did not notice any issues with the connections pre-feedline. In other words, The RX to Duplexer and TX to duplexer, I did not see any noise induced with this being LMR cable and moving it around.

So it seems to be, based on this limited test, that LMR might be okay for those interconnects that are near the radio and PA, but anything after the duplexer (i.e. the feedline) must be a different cable type such as hardline, RG142,etc,etc.

This test was enlightening to me to see for myself how two dissimilar shields could induce noise with movement in a full duplex use case.

At any rate, thought I'd share this as it was quite a surprise to me.

-Jeremy





 
The Upper Rio FM Society is Part of Amazon's Smile
 
AmazonSmile is a website operated by Amazon with the same products, prices, and shopping features as Amazon.com. The difference is that when you shop on AmazonSmile, the AmazonSmile Foundation will donate 0.5% of the purchase price of eligible products to the charitable organization of your choice.

Every item available for purchase on www.amazon.com is also available on AmazonSmile (smile.amazon.com) at the same price. You will see eligible products marked "Eligible for AmazonSmile donation" on their product detail pages.

If you would like to take advantage of this opportunity and list the Upper Rio FM Society as your charity simply go to smile.amazon.com. In the upper right-ish part of the page you will see the words Supporting: XXXX. Hover over the little down arrow and a pop-up will allow you to change where Amazon's donation will be sent.

Then start your shopping at smile.amazon.com
The 2018 New Mexico QSO Party

The 2018 New Mexico QSO party is scheduled for Saturday, April 14 from 8:00am MDT until 8:00pm MDT, and all Hams across New Mexico are invited to participate.  Amateur radio operators from across the United States -- and the world -- will be seeking New Mexicans on HF and 6 meters during the event period, looking particularly to work hams in as many New Mexico counties as possible.  The Land of Enchantment will essentially be the "DX" on this day, making for a great time for all who participate.  Last year hundreds of amateur radio operators around the world participated, including 98 New Mexico hams and 17 New Mexico amateur radio clubs.

We are looking for hams within each and every one of New Mexico's 33 counties to participate in the 2018 New Mexico QSO Party, whether for just a few convenient hours or for the entire 12 hour period.

This is a super event for new and experienced hams alike. Operate from the comfort of your home, or combine forces with hams in your club as a club activity.  Invite a group of friends to your shack.  Hit the road as a mobile station and activate multiple counties which create much needed -- and appreciated -- point multipliers for everyone who participates in the QSO Party.  Use this event as an opportunity to introduce a neighbor or friend to ham radio.  Or rally friends and club members to set up, Field Day style, as part of the special expedition category.

This year's event is hosted by the Los Alamos Amateur Radio Club.  Great-looking plaques will be awarded and participation certificates will be available for those desiring one.  Complete details, rules, prize information, and more can be found on the New Mexico QSO Party website at www.NewMexicoQSOParty.org

 

Upcoming Events and QSTs

Technician Class - The El Malpais VE Group will be doing a Technician Class on April 27-28-29. It was be Fri from 1800-2100, Sat and Sun from 0800-1700, with testing around 1530 on Sunday.
 
Spring Tailgate - The 2018 Spring Tailgate us sponsored by Amateur Radio Caravan Club and will be held from dawn to 10:30 AM on April 28 at Stoneface Tavern  - North Parking Lot. 8201 San Pedro Drive NE in Albuquerque (on San Pedro Dr at Carmel Ave, 2 blocks north of Paseo Del Norte). See http://caravanradio.org/ for more info.

The class will be at the APD NW Area Command on Ellison Blvd NW. It is right across Cibola HS. There is no charge for the class (there is a $14 fee for the test), but we highly recommend you buy the ARRL Technical Level Book. It is $29.905 from ARRL, plus shipping. Our instructors can buy them for $24 with no postage. The manual has all the test questions and background and is a good reference to the rules. You may find one on EBay or Amazon, but make sure it is the 3rd Edition. Any other edition will not the correct questions. We will also provide some other info on clubs, practice tests, and handouts on repeaters. About 98% who take the class pass the exam.

If you are interested, contact Jim Hunter, NM5JH, at hunterabq@centurylink.net or at 897-2939. We can take about 20 folks, and this may be the last class before the new question pool comes out July 1, 2018.

Trivia on the Air - Tuesday evenings between 8 and 9 PM on the Upper Rio repeater network

Renew your Membership - Remember you can check your membership status and renew your membership with a credit card via the web. Visit www.urfmsi.org/wp/join-upperrio

Be sure to check the Upper Rio web site for up-to-date information

Copyright © 2018 The Upper Rio FM Society, All rights reserved.


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