Category Archives: Ham Radio

Podcast Signals and Noise

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step1_ipodnano_whiteI’ve posted before about being a fan of podcasts (those mp3 file “radio shows” that don’t use radio). There are so many decent podcasts out there to choose from, I keep my iPod Touch loaded up with all kinds of mp3 content. Actually, my taste includes topics outside of tech, but that is what I’ll focus on for this blog posting.

One thing I have noticed is that the ham radio podcasts on my mp3 player are getting pushed aside by other tech shows. I think it is driven by the signal-to-noise ratio of the ‘cast. With so many to choose from, I have become less tolerant of rambling commentary, crappy audio and marginal content.

I don’t want to be overly critical, since it takes real work to produce a quality podcast. I have enough trouble keeping up with this blog. I would not be able to do a decent job of an audio podcast and you probably don’t want to hear my voice anyway. (I have a radio face and a CW voice.)

So what am I still listening to these days? Here’s my favorite tech-related podcasts, in rough order of priority:

  • Amateur Radio Newsline
  • Buzz Out Loud (CNET)
  • Cranky Geeks (John C. Dvorak)
  • This Week in Tech (Leo Laporte)
  • Slashdot Review (SDR News)
  • Tech5 (John C. Dvorak)
  • CNET News Daily Podcast
  • This Week in Amateur Radio (TWIAR.org)
  • PC Mag Radio

So the only remaining ham radio ‘casts are Amateur Radio Newsline and TWIAR. AR Newsline is the old standby that I used to listen to on the local 2-Meter repeater, usually interesting and well done. TWIAR has some good content but it often tests my patience with drawn out introductions and weird sound effects. Keep the fast-forward button handy on that one. Slashdot Review sets the standard for “get to the point, say something interesting and move on.”  We need more shows like that. CNET News does pretty well, too.

Oh, I should mention Ham Radio Podclass, which I recommend to students studying to pass their next license exam.

I’ll toss in a couple of non-tech wildcards for you to consider:

  • WNYC’s Radiolab – “Science meets culture”, usually thought-provoking and well-executed
  • The Moth Podcast – People telling true stories without notes in front of a live audience
  • Common Sense with Dan Carlin – a fresh, logical approach to politics that generally annoys both Democrats and Republicans

So what are you listening to? Give me some fresh ideas.

73, Bob K0NR

This Spewed Out of the Internet #13

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0511-0701-3118-0930Things have gotten a little busy for me, so sorry about going dark on blog postings. I had several weeks of business travel, followed by a wonderful trip to the Caribbean. Unfortunately, no ham radio action on any of these trips.

As usual, K3NG has posted some interesting stuff on his blog. First, he commented on Amateur Radio Liberation Day, then he had a good post on The Problem of Closed Source and Proprietary Algorithm Modes.

The Fi-Ni report explained the mysterious reappearance of the 15 Meter band.

After pestering hams with announcements that the new ARRL web site is about to be turned on (drum roll please….), the League had to back off and announce that it just wasn’t quite ready yet. It would be a lot more effective to launch the web site, then promote it. That way, when people go to check it out, it is actually there.

The FCC decided that it would be a good idea to allow a remotely-controlled robot to use 430-448 MHz as a radio control link. These robots are intended to be used by law enforcement agencies to enter hazardous areas without endangering personnel. I guessed they missed the fact that the 70 cm ham band is home for thousands of FM repeaters in the U.S. This is yet another lame spectrum management decision by the commission. (See K3NG’s post on this topic.)

– 73, Bob K0NR

Results from the 2-Day Technician Class

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Radio MikeWe finished up the second and last day of our 2-day Ham Radio Technician License Class. The class ended with a VE test session, which was done by one of the local VE teams. We had 19 out of 21 students pass Element 2, qualifying them for a Technician Class License, for a 90% success rate. A handful of the students gave the General test a try and some passed that, too. We were very pleased with the level of interest in the class and the success rate on the exams.

Our learning objective was to have the students pass the Tech exam and know enough to be able to get on the air and operate a radio on the bands above 50 MHz.

The basic approach we used was to have two all-day classes, held on two consecutive Saturdays. We carefully developed a schedule that got us through all of the material and made sure we kept the class moving through it. We had originally looked at a one-day ham class but decided that was just too much material for one day. On the other hand, we did not want to go the traditional route of meeting once a week for 8 or more weeks. We didn’t think the instructors or the students would last that long! In the end, we chose an intense two-day approach, but made it clear to the students that they had to study the book in advance to be successful with this compressed approach.

We used the Gordon West Technician License guide, which is a very focused text, which ties the material directly to the exam questions. We also recommended the ARRL Ham Radio License Manual as another good reference book.  The ARRL book provides a broader context and includes material that is not required by the Technician exam.

One important point: I found this to be a very fun and motivating activity. It forced me to take a fresh look at amateur radio and really think about how to efficiently convey the material. Seeing a group of students get excited about ham radio gave me a spark of energy. Think about this if you are looking for some way to get re-energized in ham radio.

We have a waiting list for our next class, so it seems we need to do this again…soon.

73, Bob K0NR

Time to Change Part 97?

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when-all-else-fails-logoPart 97.113 has been the topic of much discussion lately, ever since the FCC communicated a rather narrow interpretation of the rules. See my previous post on this topic for more background information. From the ARRL web site, we find that the ARRL Board of Directors has chimed in:

The Board instructed the ARRL staff to seek a change in Section 97.113(a)(3) of the FCC rules to permit amateurs, on behalf of an employer, to participate in emergency preparedness and disaster drills that include Amateur operations.

This is not really a surprise and despite the usual criticism coming from some quarters, I am encouraged that the board sees this as an issue that requires action.

N5FLD lists the specific wording that the ARRL Board has approved, expressing some concern about the particular text chosen. I think we are clearly headed towards the standard FCC rule making process that will give everyone their say and, hopefully, we’ll arrive at a reasonable decision.

The February issue of CQ Magazine, arrived in the mail today, with a W2VU editorial taking on this topic. Rich points out that if you really want to get picky about it, ham radio publications are at risk due to a narrow interpretation of Part 97.113. For example, if an author is getting paid to review a new ham transceiver for publication in CQ, can he actually put it on the air without getting the foul flag thrown for “pecuniary interest”? So CQ wants to broaden the discussion, and has their own proposal for Part 97.113.

My read: stay tuned as we hash through this. There is enough support (based on good reasoning, I think) that this issue will get addressed. But it will take some time.

73, Bob K0NR


This Spewed Out of the Internet #12

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0511-0701-3118-0930Things have been busy around the K0NR household with Christmas, New Years, a general strategy of goofing off but having to go back to work in January.

Here’s a few things that have gotten my attention lately.

It seems that some of our pirate radio friends down in Texas think the FCC does not have jurisdiction over the Republic of Texas. See K3NG’s blog posting.

I came across Les N1LF’s blog: Big Iron: Chasing VUCC on Indoor Antennas. I am inspired by someone making the most of his station limitations and chasing VUCC anyway.

Wired Magazine reports that hearing loss is in decline even though we insist on shoving iPod and Walkman earbuds in our ears.

Then Wired publishes a totally lame article about increasing the intensity of a laser pointer. The most likely result is a toasted laser pointer.

The new Technician License question pool has been released and will take effect in July 2010. I took a quick look at it since I am involved in teaching a Tech License Class. It looks like some additional technical topics such as diodes, capacitors, inductors and decibels have been added to Element 2. Yes, that means the exam is probably more difficult than the current one.

The earthquake in Haiti is gaining lots of attention, inside and outside of the amateur radio community. Be sure to stay clear of the emergency nets and let these guys do what they can.

– 73, Bob K0NR

The Class is Full

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hamWow, the interest in the Ham Radio Technician License class has been intense! I was thinking we’d get 8 to 10 students. So far I’ve had over 30 people ask to be registered for the class but we had to cap it at 24. And some of our publicity efforts are just starting to kick in.

I also noticed this item from the ARRL Web Site:

2009 Sees Surge of New Amateur Radio Licensees

Don’t these people know that ham radio is an obsolete pastime for guys over 65 years old?

73, Bob K0NR

Circuit From the Past

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I was trying to provide some semblance of order in our basement, which is the storage area for my extensive collection of great radio and computer treasures (sometimes referred to as “junk”). I ended up wading through piles of stuff that I didn’t even know I had. It was like Christmas all over again!

I came across this little gem built into a RadioShack enclosure:

IMG_3348s

I guessed that it was a Code Practice Oscillator and that I must have built it some time ago. I had a vague recollection of the project. It certainly looked like something I might have built. There was a straight key in the same box that plugged right into the key jack.

I opened the inside and found this circuit board populated with through-hole parts. Replacing the 9V battery with a fresh one, the circuit came to life. A little action on the key and the sound of Morse Code filled the room.

IMG_3346s

I was curious about the design. There is one integrated circuit on the board but it was labeled only with a proprietary part number. What would I have used to built a code practice oscillator? Probably a good old 555 timer, so I pulled up an online datasheet for that part and got its pin out.

Then I started to do a some lite reverse engineering of the circuit and this partial schematic diagram appeared:

scan0003

The circuit is not complete — I just sketched out enough to confirm that the design was based on the 555 timer.  There is a lowpass RC filter on the 555 output to round out the square wave before it is fed to the speaker. It’s interesting that the key connects to the reset pin on the IC. I think this was to ensure a clean start up of the oscillator, to eliminate any frequency chirp.

So that’s a little diversion I had this weekend. Now back to cleaning out the basement.

73, Bob K0NR

Amateur Radio: Not an Emergency Radio Service

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arrlnewlogo-transWell, that’s what the FCC says: the Amateur Radio Service is not an emergency radio service. K1ZZ’s QST editorial quotes the FCC and points out that the mission of the Amateur Radio Service is indeed broader than emergency communications. (The FCC does recognize the role that amateur plays in emergencies — see this web page.)

Lately, I’ve noticed a number of blog postings and other statements from hams that define amateur radio way too narrowly. The common thread is taking the part of ham radio that is most important to them and arguing that Real Ham Radio is focused on that segment of the hobby/radio service.

For some folks, amateur radio is emergency communications (only). Others argue that only technical pursuits are true ham radio and those appliance operators are just holding us back. For others, ham radio is defined by getting on the air and operating (might be QRP, might be contesting, might be something else).

I think K1ZZ got it right….the purpose is broader than that. Just go read Part 97.1 of the FCC rules:

The rules and regulations in this Part are designed to provide an amateur radio service having a fundamental purpose as expressed in the following principles:

(a) Recognition and enhancement of the value of the amateur service to the public as a voluntary noncommercial communication service, particularly with respect to providing emergency communications.

(b) Continuation and extension of the amateur’s proven ability to contribute to the advancement of the radio art.

(c) Encouragement and improvement of the amateur service through rules which provide for advancing skills in both the communications and technical phases of the art.

(d) Expansion of the existing reservoir within the amateur radio service of trained operators, technicians, and electronics experts.

(e) Continuation and extension of the amateur’s unique ability to enhance international goodwill.

Let’s reject the narrow view and think a bit broader.

73, Bob K0NR

Amateur Radio Tech Class

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Ham Radio Two-Day License Class

Monument, Colorado

Saturday Jan 30 and Saturday Feb 6 (8 AM to 5 PM)

Tri-Lakes Monument Fire Station 1

Sponsored by the Tri-Lakes Monument Fire Radio Association

The Technician license is your gateway to the world-wide excitement of Amateur Radio …

  • Earn your ham radio Technician class radio privileges
  • Pass your FCC amateur radio license exam right in class on the second day
  • Multiple-choice exam, No Morse Code Required
  • Live equipment demonstrations
  • Learn to operate on the ham bands, 10 Meters and higher
  • Learn to use the many VHF/UHF FM repeaters in Colorado
  • Find out how to participate in emergency communications

There is no cost for the class

However, students must have the required study guide:
Gordon West Technician Class guide $18.95
And pay the FCC Exam Fee: $15.00

Advance registration is required (no later than Jan 25th).

To register for the class, contact: Bob Witte KØNR   techclass@k0nr.com

For more information on amateur (ham) radio visit www.arrl.org
 or www.wedothat-radio.org

Update: As of Jan 6th, the class is full. We have had a surprising number of people interested in this class. We are keeping a waiting list and we are likely to offer another class later in the year.

Hacking Away at D-STAR Hardware

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dstarWe’ve been looking at optimizing the performance of the D-STAR repeater here in Monument (W0TLM, 446.8875 MHz), so I’ve been searching the web for information on what other groups have uncovered. Not surprisingly, there has been some creative reverse-engineering and re-engineering of the ICOM D-STAR repeaters.

Here’s a summary of some Good Stuff that I found:

1. NU5D paper on DSTAR Repeater Modifications & Interference Testing

2. A good overview of the ICOM D-STAR repeater block diagram and a few modifications to the ICOM repeaters on the dstar.ca web site

3. The N5EBW LED Board – a drop in board to add transmit/receive LEDs to the ICOM D-STAR repeaters

4. The Utah VHF Society D-STAR page — some of the best technical information and practical evaluation of D-STAR technology

5. A Look Inside D-STAR Modulation – an article I wrote for CQ VHF magazine that explains the vocoder and modulation scheme in D-STAR.

If you come across other D-STAR resources, please let me know.

73, Bob K0NR

This Spewed Out of the Internet #10

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Here’s a few more tidbits of internet brilliance that caught my attention:

K3NG noticed that a pirate radio broadcaster told the FCC that he is not under their jurisdiction because he is in the Republic of Texas. Don’t Mess With Texas.

Looking for professional grade audio performance? Then you need this Audio Grade Power Outlet. Be sure to read through the comments.

The Fall ritual of changing our clocks due to Daylight Saving Time is over. While some of our politicians keep telling us this saves energy, that theory has been largely discarded.  My proposal is to have everyone on the planet switch to UTC. Seems simpler to me — fewer errors in my log book.

Its official: Laptop computers fail way too often. Square Trade published a study that compares laptop and netbook failure rates (all of them are too high). What ever happened to Total Quality Control?

Cracked.com made a run at describing what the world would be like if the Internet disappeared today.

NASA has concluded that there is water on the moon. Holy Cow, really? This is a major discovery. Of course, some people are upset that NASA is abusing the moon by crashing spacecraft into it.

One final thought: Thursday is Thanksgiving in the US, so stop your whining and find something to be thankful for.

I will if you will.

73, Bob K0NR

2009 June VHF QSO Party Results

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arrlnewlogo-transThe results of the June VHF contest have been published online and in the December issue of QST. I operated from our cabin in DM78, near Trout Creek Pass with temporary antennas up for 50 MHz and 144 MHz (3-element Cushcraft Yagi on 50MHz and a 2M9 on 144 MHz)  It was mostly a two band effort in the low power single operator category, with a few additional contacts on 440 MHz FM.

VHF contests are mostly a regional competition since the scores depend so much on adjacent operating activity. Here’s the scores for the Colorado Single Operator Low Power category:

# Call Score QSOs Mult Class Section
1 N0POH 73,225 419 145 A CO
2 K0COM 38,532 322 114 A CO
3 N0HF 29,718 254 117 A CO
4 K0NR 28,197 238 117 A CO
5 N0YE 14,112 154 56 A CO
6 KB0YH 13,855 163 85 A CO
7 W0EPC 7,812 126 62 A CO
8 WB5PJB 6,050 97 55 A CO
9 K0CS 4,928 88 56 A CO
10 K0UK 1,316 47 28 A CO
11 KC0VFO 1,140 53 19 A CO
12 W0PSS 621 26 23 A CO
13 AB0SF 440 22 20 A CO
14 N0HIO 352 22 16 A CO


Congrats to Wayne N0POH for leading the Colorado Section (and the Rocky Mt Division).

My 28k score is less than the 39k I scored in 2008 (See Awesome June VHF Contest).  I have shifted my focus in the contest to picking up new grids, especially on 144 MHz. I qualified for VUCC on 6M, 10 GHz and Satellite years ago but have never confirmed the required 100 grids on 2 Meters. If I was after the best contest score, I’d be trying to add higher bands to the portfolio, especially 1.2 GHz.

73, Bob K0NR

Colorado QSO Party Results

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colorado-flagThe results of the Colorado QSO Party have been posted on the PPRAA web site. I had previously written about this, but I never got around to posting my score after the contest.

Here’s the email I sent to the various club email lists:

The CO QSO Party succeeded in getting me back on the HF bands. I operated from our cabin in Park County with 100 Watts to a half-size G5RV in the trees. I also had 50W to a 2M yagi (2M9) antenna. Only worked WA7KYM in Wyoming on 2M SSB and he was not working the contest. I did pick up a few contacts on 2M FM, which was fun. All contacts were on phone.

I spent a considerable amount of time on 40M but it did not yield much. The exchange of “name” was quite natural on phone and added to the laid back flavor of a state QSO party. All in all, a very fun time.

At times, there were 4 contests running near 14.250 MHz: CoQP, Hiram 140, All Asean DX and another one I did not identify. Lots of “CQ Contest” and lots of confusion 🙂

Band    QSOs    Pts  Sec   Mul
   7       3      6    1    1
   7       1      2    1    0
  14      70    152   31    0
 144       5     10    3    1
 144       1      2    1    0
 420       1      2    0    0
Total      81    174   37   2
Score: 6,786


I placed 3rd in the In-State Low Power Phone – Single Operator category, behind Dan W0RO and Brian N5ZGT. A highlight during the contest was working my good friend Denny KB9DPF in Fort Wayne on 20 Meters. It has been years since we had made contact on the HF bands.

Thanks to the Pikes Peak Radio Amateur Association for sponsoring this contest.

– 73, Bob K0NR

This Spewed Out of the Internet #9

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0511-0701-3118-0930I have been traveling quite a bit lately for work, so here’s a catch up on a number of things spewing forth from the interwebnet.

I’ve recently re-discovered High Frequency Electronics Magazine, edited by Gary Breed, K9AY. This is a top quality trade pub that targets RF design engineers. In Gary’s September editorial, he highlighted the environment that the college class of 2013 grew up in….such as “text has always been hyper.”

I came across this summary of Top Ham Radio Blogs. They clearly have excellent judgment, since my blog is listed.  🙂

Computer World published this article,  Want to bone up on wireless tech? Try ham radio, a good read on the experimentation side of amateur radio written by John Edwards, W6JE.

Google’s Eric Schmidt talks about the future of the web…some interesting thoughts.  I hope his prediction of 100MB broadband comes true…but I am not expecting it to come down my road any time soon.

KB9MWR posted an interesting article about the radio range of D-STAR.

Ham radio saves the world (again)…. hams assist rescue on Catalina Island. This reminds me of when  I was out climbing Uncompahgre Peak and radio’d in a fallen hiker report.

Last weekend was the CQ Worldwide DX Contest (SSB version), so I did get on the air for a few hours. Mostly, I got clobbered on 20 Meters with my 100-Watts-to-a-dipole station being overrun by the Big Gun Stations. I did manage to work some DX on both 15M and 20M.

The FCC actions concerning EmComm and Part 97.113 have exposed different views on the role of amateur radio in emergency communications. See the comments on my blog posting, this article by Steve K9ZW and N5FDL’s blog. There seems to be some pent up frustration with ham radio EmComm folks coming from some corners of the ham community.

I encourage everyone to go back and read Part 97.1, the Basis and Purpose of the Amateur Radio Service. It lists five different items as the purpose of amateur radio, all of which are relevant and important. I’d also suggest that everyone lighten up just a bit (and be sure to stay on your meds).

73, Bob K0NR

Time to Change the FCC Rules for EmComm?

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fcc-1The FCC continues to drive out any ambiguity on how it interprets Part 97.113. (See previous post EmComm Trouble From the FCC. ) On October 20th, the FCC released Public Notice DA-09-2259, which reiterates the principle of no amateur radio communication on behalf of an employer, even if the employer is a government agency such as a fire or police department. OK, I think they got that point across.

The FCC also described a process for requesting a waiver of this rule for a specific emergency preparedness drill. A governmental entity, not the amateur radio operators involved, must apply to the FCC for a waiver in advance of the drill. According to N5FDL, the FCC intends these waivers to be for very specific events and not a regularly scheduled activity such as a weekly net. This can help facilitate a major event but is still fairly limited. I wonder how many waiver requests the FCC be receiving? I suspect there will be many.

A group of radio amateurs, The Amateur Radio Policy Committee, consisting of N5GAR, WB6NOA and N5FDL have filed a Petition for Rule Making with the FCC to address this situation. Basically, they propose that an additional item be added to the section of  rules (Part 97.111) that calls out Authorized Transmissions:

(6) Transmissions necessary for disaster relief or emergency response, including training exercises, planning, drills or tests, without regard to whether the amateur operator has related employment, where the transmissions are for the exclusive use of amateur radio operators for noncommercial purposes.

This seems like a reasonable and measured approach to changing the rules to support emergency communications training activities, without opening the door too wide. I am not sure why they proposed to modify Part 97.111 instead of 97.113 where other employment exceptions are handled (e.g., control operator of a club station that sends telegraphy practice, teacher in a classroom setting). The RAIN Report has an interview with N5FDL concerning this petition.

I still believe the FCC could have avoided this ruckus with a slightly more liberal interpretation of the rules. They didn’t do that, so now we will have to go through the rule making process to deal with the situation. I suppose that the FCC could decline to address the issue but this seems unlikely to me given the legitimate public interest in supporting emergency communications. (Anyone remember 9/11 ?) We’ll likely get to a reasonable outcome that protects the amateur radio service from undesirable encroachment while still enabling emergency communications training.

What do you think?

73, Bob K0NR

2009 Fall TechFest

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Announcing the 2009 Fall TechFest, an all day technical program for the continuing education of ham radio operators

Schedule of Workshops
(times are tentative)
November 7, 2009
Morrison, Colorado

Time

Topics

9:00 –   9:50

Digital Modes

Jim Stitt, KAØNZZ

10:00 – 10:50

Ohm’s and Kirchhoff’s Laws

Larry Weinstein, KØNA

11:00 – 11:50

Block Diagrams And Schematics

Steve Finch, AIØW

12:00 – 12:50

Lunch (on your own) Question and Answer Session for those who stay to eat

1:00 – 1:50

What Test Equipment to Buy

Bob Witte, KØNR

2:00 – 2:50

Taking the Mystery Out of SWR

Bill Rinker, W6OAV

3:00 – 4:00

Propagation Basics

Larry Weinstein, KØNA

Additional Information

When

 Saturday, November 7, 2009:  9:00 a.m. – 4:00 p.m.   Check in:  8:00 – 8:45 a.m.

Registration

 Space is limited! Pre-registration recommended. Please e-mail k0nnc@arrl.net to pre-register. Please pay at the door.

Cost *

 $5.00 (cash only)

Where

 The Inter Canyon Fire Department Station #1. Go to www.intercanyonfire.org. Click on “Our District”, then “1”, and then “Google Maps – Station 1”. The address is 7939 South Turkey Creek Road, Morrison, Colorado OR check our website – www.na0tc.org.

Carpooling is recommended.

Refreshments

 Free coffee and water will be available. Muffins, rolls, soda pop will be available for purchase (cash only). PLEASE BRING A SACK LUNCH.

*The 285 TechConnect Radio Club will donate 50% of net proceeds from this event to Deer Creek Elementary School Ham Radio Program.

Website:    www.na0tc.org for more information.

Talk-in frequency 147.225 MHz

Handouts will be available on the website one week before the TechFest.

Pacifico Fake Ham Radio

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I was flipping through the November 2009 issue of National Geographic Adventure magazine and noticed an advertisement with the title “building your own ham radio”.

Wow, what’s up with that? It was an ad for Pacifico beer. The text in the ad says:

Become the envy of friends and locals as you join the elite club of fake ham radio operators worldwide.

A little searching on the interwebnet found this video:

Let’s see: beer, sand, beach, palm trees and ham radio…. now that is something I can relate to (but it might be a niche audience)!

73, Bob K0NR

AMSAT Focuses on LEO Cubesat

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amsat-logo-semi-officialAMSAT has recognized that they need to get some new hardware flying in space and is now focused on getting a small LEO satellite developed. AO-51 (originally called ECHO) has been a very popular satellite and one of the few clear successes from AMSAT in recent years. It appears that the AMSAT engineering team has recognized this and wants to emulate that success.

>From AMSAT HQ SILVER SPRING, MD.
October 18, 2009
To All RADIO AMATEURS
BID: $ANS-291.01

The Board of Directors has adopted the Engineering Task Force
recommendation that low-cost launch options be immediately pursued.
The AMSAT engineering team will develop a 1U CubeSat design effective
immediately. Tony Monteiro, AA2TX, Vice-President of Engineering said,
"We are recommending an approach that gets AMSAT back up in space with
new satellites by leveraging the skills and technology we have today."

The new AMSAT CubeSat's initial capability is planned to add to the
popular low-earth orbit FM transponder fleet allowing hams to continue
to use their existing handheld and portable antenna systems. This also
allows an accessible entry path for new satellite operators to get
started. The existing FM satellites are starting to show their age.

The flight version of ARISSat-1 has been developed to fit into the
CubeSat model. AMSAT's flexible Software Defined Transponder (SDX),
simplified IHU, power control subsystem, external interfaces to ex-
perimental payloads and cameras will now allow a modular approach to
mission design using proven subsystems and components. The ARISSat-1
mission planned in 2010 will be the initial flight test of AMSAT's
modular satellite.

Here are some of the highlights ...

+ AMSAT will develop comparable AO-51 level of performance packaged
  into a 1U CubeSat. This includes a U-V transponder, V telemetry,
  U command receiver, IHU, power control. This can be done with our
  modular design.

+ This will be a U/V FM Transponder, not done before in a 1U CubeSat,
  which can be worked with a HT and a simple antenna. CubeSat power
  limitations are planned to be addressed through research and devel-
  opment of deployable solar-cells.

+ AMSAT will make our open-design satellite modules and technology
  available for other satellite teams to build into their missions.

+ This new approach will provide a reliable radio link for future
  CubeSats allowing university teams to concentrate on their scientific
  objectives.

+ The modular nature of the AMSAT CubeSat system will allow add-on
  missions utilizing several different types of modulation and band-
  width. These can be pursued with future low-cost CubeSat launch
  opportunities. 

AMSAT President, Barry Baines, WD4ASW Annual Meeting Powerpoint
Presentation has been posted at http://www.amsat.org

[ANS thanks the AMSAT Board of Directors for the above information]

/EX

AMSAT has often struggled with where to focus its energy, having a strong desire to get a High Earth Orbit (HEO) satellite deployed, but failing to pull it off. Also, there is considerable tension between doing something relatively simple (like an FM bird) and more advanced capability (linear transponder and advanced digital modes). Many of the techies in AMSAT want to do the next cool thing technically, and I do appreciate that. That desire sometimes drives things a bit too hard and has generated some very complex satellite designs. I am an AMSAT member but I am not in the loop on all the internal AMSAT politics.  (Be thankful for that, I think.)

I have had a lot of fun with the FM LEO satellites, activating and chasing grids. It is like a scheduled DX opening… you know when the “band” is going to open (for about 10 minutes) and you better work them fast. It has some of the same problems as working DX in that the single channel pile ups on the satellite can be very frustrating. I managed to check the box on Satellite VUCC and I activated a number of rare grids (e.g., FK52 as PJ4/K0NR).

Would I rather have a super whizzy HEO bird that sits overhead for hours supporting a wide swath of frequencies and all kinds of neat digital modes?  You betcha. But it seems that we don’t have the capability to pull that off.

What do you think?

73, Bob K0NR

Update on the Crossband Repeater Project

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In a previous blog posting, I wrote about the construction of a portable VHF/UHF crossband repeater. I published the results of this project in my FM/Repeater column for the Fall 2008 issue of CQ VHF Magzine. I’ve adapted portions of the article to provide an update here.

To deal with the issues of identification and control, I decided to use a repeater controller to control two independent 2M/70 cm transceivers. Most repeater controllers are set up for conventional repeater control with a fixed receiver and fixed transmitter. What I needed was a controller that incorporated the concept of two independent transceivers that could be linked together, independently controlled and independently identified. The NRHC-6 Bridging Repeater Controller is designed to handle this specific case of connecting two transceivers. The block diagram of this crossband repeater system is shown in Figure 1.

Figure 1. Repeater system block diagram
Figure 1. Repeater system block diagram

I used a pair of FT-7800R transceivers which have a packet port on the rear panel that provides a convenient interface point for the repeater controller. This port has the required transmit audio, receive audio, PTT line and squelch line. The squelch line indicates the condition of the receive squelch, including the effects of CTCSS decode if enabled in the transceiver. (Not all transceivers behave this way… some only provide carrier squelch even if CTCSS decode is enabled.) Table 1 shows the signals available from the packet port and how they are used in the repeater interface.

Table 1. FT-7800R Packet Port

Pin

Label

Description

Repeater Interface

1

PKD (Data In)

Packet Data Input

Transmit Audio

2

GND

Signal Ground

Ground

3

PTT

Ground to Transmit

PTT

4

RX9600

9600 bps Packet Data Output

5

RX1200

1200 bps Packet Data Output

Receive Audio

6

PKS (SQL)

Squelch Control

CAS

The NHRC-6 controller has a versatile feature set that requires some programming to make it work. It supports two radio ports which can be configured to handle two back-to-back simplex radios. The controller has DTMF control, which can be accessed from either radio port. The five saved setups are handy for storing away specific repeater configurations. Each radio port can have its own courtesy tone and CW identifier, along with the usual set of hang timer, ID timer, timeout timer, etc. The crossband repeater can be turned on and off remotely using DTMF on either band.

Figure 1 shows two separate antennas, one for 2 Meters and one for 70 cm. In most cases, I use one dualband antenna and a 2M/70 cm duplexer to allow the two radios to feed the antenna. I also keep the radios set at less than full power to minimize the heat dissipation problem.

figure-5-crossband-repeater-system
Figure 2. The crossband repeater in a 19-inch rack mount case.

This crossband repeater is housed in a portable case that has standard 19-inch rack hardware (Figure 2). The two transceivers are mounted to a 19-inch shelf using their normal mobile mounts. The NHRC-6 controller has its own 19-inch rack mountable chassis. The case has a front and rear panel covers that snap on, protecting the equipment during transit. The system runs off of 12 VDC. I did not include an AC power supply inside the case. Depending on the location, I simply connect the repeater to a 12 volt car battery or a compact AC switching power supply.

I’ve used this repeater as a standalone UHF repeater by adding a small mobile duplexer to provide transmit/receive isolation. Of course, in this case, the two transceivers both operate on the 440 MHz band with 5 MHz offset. I’ve also used it as a crossband repeater, usually to extend the range of a 2 Meter repeater.

– 73, Bob K0NR

Golf November Tango

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when-all-else-fails-logoAmateur radio has a deep tradition of providing emergency communications during all kinds of disasters. Of course, some emergencies are more urgent and serious than others.

The Golf November Tango frequency is an important frequency to always have programmed into your radio. Established as 146.55 MHz ( FM simplex, no CTCSS), the GNT Frequency is the critical logistics channel for certain types of incidents (to use ICS terminology).

This all started when three ham radio operators found themselves stranded on the shore of Lake Michigan. Well, actually they were not so much stranded as just sitting there watching the waves roll in. Without warning, they found themselves getting thirsty without any liquid refreshment in sight. Rather than make the long, treacherous walk back to the beach house, a 2M FM transceiver was employed to make the critical call. Fortunately, the wives of these dehydrated amateurs were also FCC licensed amateur radio operators monitoring the designated GNT frequency.

Without delay, communication was established with the beach house and the critical resupply of Gin and Tonic was delivered. There was some thought that the guys on the beach were just being lazy, but the requested GNTs were quickly dispatched anyway.

After that incident, 146.55 MHz was established as the GNT Frequency for all of North America.

Like they say, When All Else Fails.

73, Bob K0NR