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Author Topic: Recommended Equipment for New Operators  (Read 8389 times)
KE4SKY
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« on: August 01, 2001, 08:04:51 AM »

Newly licensed amateurs are enthusiastic and we like to capture that energy to involve them in ARES / RACES activities and training to bring them up to speed quickly.  It seems that most new operators get a handie-talkie for their first rig, but we try to encourage mobile rigs as first rigs for new operators of driving age.  A portable does make sense for those who don't drive, or who commute using public transportation, or those with limited mobility.  

General recommendations are either a single-band 2-meter or dual-band 2m/440 or 2m/220 rig capable of 25 watts, for simplex operation, also having a lower power (such as 5w) for conserving the battery, capable of operation from an external 12V battery, frequency agile with selectable repeater offsets, ten or more field programmable memories, and CTCSS encode capable.  Rugged construction, simplicity of operation, common-sense controls and a large, easy-to-read display are desired.

If all you have is an HT, you should strive to get a better antenna than the factory "rubber duckie." A telescoping half-wave on 2 meters or a flexible dual-band which is a 1/2 wave on UHF and full-sized quarter-wave on VHF work well.  An HT for emergency communications should also have the means to be powered from an external battery, such as a gel cell battery, and have an auxiliary battery case for AA cells so you can continue to operate if the power goes off when you can't recharge your NiCd pack.  A small "brick" amp which will provide 25w or more when driven by your HT at its low power setting and compact enough to be backpacked with a gel cell battery, 25 feet of coax and a wind-up J-Pole antenna you can pull up into a tree is a good idea.

This is by no means a complete list of criteria, but should get the thread going.  I'm sure folks would be interested in other's experience and recommendations on equipment for EmCom!

73 de KE4SKY
Virginia State RACES Training Officer  


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KB9YIA
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« Reply #1 on: August 08, 2001, 06:39:17 PM »

I think I fit your prediction of the newly licensed amatuer.  I went with the HT setup largely due to the flexibility of taking the thing everywhere.  (Even into the office here as a work/type/listen!)

It's helpful to see your recommendations on essential gear.  I have already invested in the long 19" flexible antenna and the dual-band mobile brick amp.  I've been thinking about using some type of battery system to make that brick more useful/portable, but it hasn't happened yet.

I am not familiar with the gel cell varities and would like to hear a bit more about them.  (e.g.: how do they recharge, how heavy and large etc...)  I was even thinking about the "car-starter" battery units that can jump start a car and run various devices through a cigarette lighter plug.  However, I hadn't really given much thought about shoving one of those into a backpack!!!  They run on the large side.

Does anyone have experiences with these batteries?

The j-pole antenna is coming up on my antenna building calandar so I 'll be able to check that off soon.

Emergency communication was a major reason for getting my ticket.  Now it's time to put it to good use.  Thanks for the thread!

Steve
KB9YIA
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KE4SKY
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« Reply #2 on: August 09, 2001, 03:17:01 PM »

Glad to hear that you got a better antenna and are looking at auxiliary power.

Battery recommendations for EmCom are contained in Unit 5, Family and Personal Preparedness, of the Virginia ARES / RACES Basic Operator Course, located at http://www.va-ares.org/Training/training.html

My experience has been that the commercially assembled battery packs targeted to amateurs contain small batteries of very limited capacity, dressed up in  fancy packaging with unneeded "bells and whistles" which make them more complicated, reduce their reliability and increase their cost.

The popular "Power Station" contains only a 7ah battery.  It will may run your HT or a laptop and TNC for a while, but will go flat in short order if you try to use it to power an FM mobile or HF rig! Larger models touted to jump start cars are still only about 17ah.  They'd power an HT, laptop and TNC for a portable packet station, but are inadequate to operate a mobile rig except at low power, or an HF rig at anything above "QRP."

The Quantum battery packs produced for photographic use are very high quality, specialized units, but also expensive and of limited capacity. They contain a 2.4 amp-hour battery which is OK for running an HT, but not larger equipment. You can drain one of these before finishing on an all-day public service event.

A good rule of thumb for sizing auxiliary batteries is to ensure one amp-hour of battery capacity for each watt of transmitter output, as a minimum!  For RACES disaster response kits double that figure.

To power an HT all day for public service events or accompanying ground SAR or damage assessment teams you are better off assembling and testing your own pack. Contact your local hospital and ask their building engineer and mnaterial management about getting their  old gel cell batteries they change out.  Most larger hospitals rotate these on four-year cycles and while they have some "age" on them, most will be good, but at somewhat reduced capacity, and they are free.  We collect TONS of batteries from Virginia hospitals for distribution statewide.  Municipal recycling programs work with battery retailers to help us recycle and properly dispose batteries we collect which fail load testing. Most of the batteries we collect are 4 years old and give us another year or two of operation before we finally recycle them.  The cost is "right."

For HTs connect in parallel two or three 2ah lead-acids.  These are flat, fit in a jacket pocket and stack easily.  Look in the biomedical engineering department, as they are widely used in portable diagostic instruments.  The larger 7ah gel cells used in the "Power Station" are common in household alarm systems and can be bought new at retail for around $20.  They will power an HT all day and fit in a military surplus ammunition magazine pouch.

My favorite battery for portable operating is a flat 17ah of the type commonly rigged in series pairs for fire alarms and emergency lighting.  These weigh about 11 pounds, but carry easily in a backpack or small briefcase.  They are great for QRP operating or for portable packet.  You can use one to power a mobile radio at low or medium power for portable operation for public service events, but they won't last long if you transmit with more than 20w.

The recommended transportable battery for EmCom, if you only have to carry the battery a short distance from your car to the operating position - not long distance foot travel, is the Battery Council International Group U1 size.  These run from 30-34ah depending upon construction, and weigh about 25 pounds.  These will power a typical mobile rig at 25 watts all day for public service events. You can run HF at 25w SSB with fairly good results for on "short path" and will lose only an S-unit or so of signal compared to 100 watts.

For serious portable HF during Field Day or for stationary backup at Red Cross chapter houses, etc. You want BCI Group 27 or larger deep cycle batteries in the 100ah range.  These are not "portable" at 65 pounds each, but are readily transportable by one person for short distances.  A pair of these mnake good home station backup.  Four in parallel are recommended for fixed repeater backup, EOCs etc.

The easiest way to charge any of these gel cell batteries is to go to www.batterychargers.com and look at the Schumacher 1.5 amp automatic battery maintainer.  This charges small gel cells and will also charge and maintain car batteries and deep cycle batteries up to BCI Group 27, though you may have to be patient.  For overnight charging of gel cells larger than 80ah, get the 6A Schumacher SE-600 or float the battery in parallel across your 13.8V regulated power supply.  Just be sure to put a couple Shotky diodes in line so that the battery doesn't backfeed into your power supply and "smoke" it if the AC power goes off and your backup system "fails to battery."

73 de KE4SKY
Virginia RACES Training Officer  

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KB9YIA
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« Reply #3 on: August 09, 2001, 06:14:45 PM »

My goodness!! That's a lot of battery knowledge!!  This is clearly something I'll need to look into further.  I really like the suggestion of checking the Hospitals.  Nothing beats FREE!!  I would imagine that Hospitals ends to err on being conservative when replacing life-dependent equipment like that.  Your repsonse gives me much to ponder.

Now for the antenna.  I just tripped across some plans for a j-pole made from 300ohm TV twin-lead at:

http://www.sedan.org/ant.htm

Is that pretty much what a "roll-up" j-pole is?  I guess I am only familiar with the "All Copper J-Pole" as described someplace in the big ARRL manual.  Something tells me that a little piece of twin-lead is going to be slightly more portable than a huge copper chunk of plumbing!!!  

Perhaps that is another device I should construct.  I wonder how it would perform.

Your thoughts?

Steve

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KE4SKY
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« Reply #4 on: August 10, 2001, 08:01:59 AM »

The twin-lead J-pole is the "roll-up" version which MFJ makes, but these are easy to make and are a good construction project for new hams.  You can also make these from 450-ohm ladder line.  The TV twin-lead versions are fine for low-power applications upto about 10w.  If you wanted a portable J-pole to use with a higher-powered rig I'd use a hard-wired version constructed from ladder-line with RG8-X for feedline.

The J-pole is a half-wave which doesn't require a ground plane.  If connected to ten or 15 feet of coax, it is handy to pull up into a tree with a throwing weight and some light cord.  This will really improve the range of an HT, or let you reduce power to help your batteries last longer.  It also helps for indoor use if you can it pull up high, away from metal objects.

The TV-lead J-pole also "works" on 440, after a fashion.  It isn't ideally reasonant there and I've no idea what its radiation pattern looks like on UHF, but people report that it seems more effective than a stock rubber duck on UHF.  Your mileage may vary...
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KF4VRB
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« Reply #5 on: August 10, 2001, 08:59:05 PM »

I posted this on another group about a month ago, but since someone wanted to know about the jump starter battery deals, I thought I'd share it here also...

After seeing a couple of those battery powered jump start booster cable things on sale, I figured I'd see if they could be of some use to me. After skipping the battery booster info, I looked into the specs. An 18 Amp hour 12 VDC battery with onboard charger, DC outlet , 8 AWG jumper style cables with heavy duty clamps, onboard power meters/diagnostic lights, and it came in one heavy duty carrying case. I have been meaning to upgrade my sole 4 amp hour dc power source/air compressor combo to something with a little more kick, and nothing but pure power (I mean the compressor is nice, but for mountain topping???) So I proceeded to pick up 2 of those jokers and took them home to charge them up. Next I picked up a 5watt and 15watt solar panel to charge my batteries when I should be so unfortunate to not have commercial power. I already had a 5watt that is slightly fragile, but works great when you are careful. The 5w solar cells will be used for charging the batteries when I just need a radio to use while camping, utilizing the 45 watt 2meter/70cm booster just for emergencys and ocassional ragchews. I could also use this to power a crossband repeat rig at the base, effectively improving the range of the handhelds in my group. If I planned on using it a little more often, then I would use both the battery packs along with the 15w solar panel. This last setup I plan on using with an HF rig to go mountain topping later this year. I also plan on making a power distribution buss for this too.
Sometimes things that have been eating away at you suddenly become clear after investing in new equipment. I have been wanting to utilze the crossband repeat Kenwood TH-79 with docking booster rig in my vehicle while doing whatever I need to.  Problems: One, I didn't want to leave my rig visible in my vehicle. Two, the DC outlet is not powered when key is not in ignition (I know easy fix, but I just do not want to do it that bad!). Three, I didn't want to run a (fused on both - & + leads)wire from the trunk to the car battery for an outlet, just call me lazy  ! Four, it would be for rare occassions and not worth the effort. And Finally Five, I didn't want an extended ragchew to leave me stranded with a dead battery. So now with these power stations I can pop one in a Secure trunk, hook up my rig to power station, reroute my coax, and hook up a small 5 watt solar panel and leave it in the back window to trickle charge the powerstation while stationary. While driving a wire plugged in the vehicles DC power, charges up the Power Stations battery. One last note about this is that the Radio in the trunk and Power Station must be secured inside, so in case you gotta bug out, your equipment will not be busted when you get done! Portable, temporary, convienent, that is what I like!


Also they worked really good doing the jump start also...

BTW I disagree with not getting an HT as a first rig. If you get the AMP and some decent antennas then the HT is much more a rig than any mobile. I have used mine as a mobile,HT, and Base with great success. If you get only a HT without the extras then I think it is too little. Only drawback to the HT with extras is you put alot of stress on the radios connectors configuring it to different uses daily. Thats why I got a second HT!!!
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KE4SKY
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« Reply #6 on: August 29, 2001, 09:14:39 AM »

The problem I've seen with trying to use an HT as your primary rig, with a brick amp to boost it, is that today's tiny HTs have only a very limited heat sink and are not built to handle the operating duty cycle that a mobile rig is.  That is inviting the radio that you depend upon to fail when you need it most.    

If you elect to use an HT to drive a brick amplifier, select an amp which provides a useful, say 10dB increase in output power, but which can ALSO be driven successfully using the portable at a lower power setting, not more than half its maximum rated output power.  If you use this precaution, HOPEFULLY the final power transistors won't fail prematurely.  

This is necessary because most amateur portables are only designed to operate at about 15-20% duty cycle, typically 30 seconds of talk time to 3 minutes of listening.  Look at your users manual or email the manufacturer and see what they tell you. A duty cycle of 20% is fine for casual repeater monitoring and idle chit-chat, but may not be adequate for EmCom when it gets "busy."

If you need to send multiple pieces of formal written traffic on a net one right after the other, as is the case in disaster work, or if you will run packet or APRS, or serve as a net control on a voice net, you may likely "cook" a set of finals on many of today's HTs in short order.  This is especially true if you power the rig at 12V from your car battery, at its  maximum output of 5 watts or more to drive a brick amp.  If you can reduce the output power of the HT to no more than 50% of its rated maximum, say 1-2 watts and can still get 25-30w output or so from your brick, then you should have adequate communications reliability and the finals should last longer.

When I first got my license I burned up SEVERAL Radio Shack HTX202s and a Kenwood TH22.  Kenwood told me flat out that I was exceeding the recommended duty cycle for an HT, pointed me to the page in the operators manual, and should buy a mobile, which I did.  My Jeep electrical system runs over 14V when the engine is running and my Radio Shack HTX202 would produce about 8w! on "high" power.  For a new licensee this seemed exciting until I came to realize that a set of finals would only last a week or two in daily communiting chat!  Radio Shack repaired the unit  three times under warranty in the first year, then replaced the radio, which soon failed again, so when I cajoled them to replace it AGAIN, I took the new rig in box with cellophone still on it to a hamfest and traded it on a public safety grade portable which I converted to amateur use and am still using. It has withstood punishment which would have destroyed several amateur rigs.  It would use it to pound tent stakes or as a wheel chock with no hesitation!  

Amateur manufacturers specs seem only to dance around rated duty cycle.  You have to read the fine print and be very direct with questions to manufacturer reps to get straight answers. I have found that NONE of the currently mass-marketed amateur HTs, even those with a Mil-Std-810CDE rating, are designed to exceed 20 percent duty cycle.  If you are serious about using your HT as a primary rig, seek an older "full-sized" model, which can run directly from 12V DC using your auto cigarette lighter plug or a gel cell battery, which also has a AA battery case so you can operate away from your car when the power is out, if you can recharge your NiCds, which is also frequency agile and can be programmed in the field from the keypad (no PC interface needed), with CTCSS encode and at least ten memories, with the largest hear sink you can find!  Those are my specs for an HT for EmCom!  

Virginia ARES / RACES has an article entitled "Getting the Most from Your Handheld Transceiver" which I would be pleased to post here.   If all you have or can afford is an HT, certainly make the most of it and a brick amp can help, but you still have to understand its limitations.  
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KF4LNE
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« Reply #7 on: September 01, 2001, 01:21:30 AM »

20% duty cycle?! i must be lucky, i use my htx 202 daily at a good 40% duty cycle on high power on my cars electrical system. i use my htx 202 in place of my htx 242 that now puts out about 1/4 watt from where i fried its final on 10 watts. i use my th 77a frequently when camping using a pair of bagphone batteries and a homebrew 'fold up' yagi made from a tv antenna, a fold up xmas tree stand and my 'walking stick', a 5 ft by 1 1/4 in peice of aluminum pipe with a aluminum end caps. i have used this effectivly to communicate back to my house about 8 miles from where i typically camp. i personally reccomend getting a good mobile first, but dont rule out the HT just yet.

Dan - KF4LNE
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