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Thread: To HF or not to HF

  1. #1

    Default To HF or not to HF

    That has been my question... Hey guys I am new to the forum and HAM radip in general. I just recevied my Technician license and am looking into building a rig. I have decided to do a mobile base station for two reasons. First off, I have an apartment so I dont want to do anything permanent. Second, I want to use my HAM setup for ARES ops and hurricane preparedness as I live in Key West and after Irma our com was out for a weeks until mobile cellphone stations were deployed which finally restored services. I would like to be able to communicate long range to the mainland in the event of an outtage. We have repeaters in the Keys but in the event of a storm they will almost certainly be knocked offline due to wind or a pwoer outtage. Is HF my only option then? Would that mean two antennaes in my setup (one for VHF/UNF and one for HF)? Are there any special considerations I will need to make? Can I mount both antennaes if needed to the front bumper guard? What equipment will I need to run both? I am doing as much research I can on the topic and plan on pulling the trigger once I have everything set. I also plan on adding a second battery and a battery isolator to cutdown on electrical noise.

  2. #2

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    Quote Originally Posted by Rapture333 View Post
    That has been my question... Hey guys I am new to the forum and HAM radip in general. I just recevied my Technician license and am looking into building a rig.
    Technician's HF voice privileges are limited to ten meters and two hundred watts. At this point in the sunspot cycle, ten meters is unreliable. Also, please specify whether you are building a radio or an antenna.

    I have decided to do a mobile base station for two reasons. First off, I have an apartment so I dont want to do anything permanent. Second, I want to use my HAM setup for ARES ops and hurricane preparedness as I live in Key West and after Irma our com was out for a weeks until mobile cellphone stations were deployed which finally restored services. I would like to be able to communicate long range to the mainland in the event of an outtage. We have repeaters in the Keys but in the event of a storm they will almost certainly be knocked offline due to wind or a pwoer outtage. Is HF my only option then? Would that mean two antennaes in my setup (one for VHF/UNF and one for HF)? Are there any special considerations I will need to make? Can I mount both antennaes if needed to the front bumper guard?
    It sounds like you are going to run coax from your apartment to a nearby vehicle. If this is the case, two antennas are probably necessary. You may have to experiment with the actual mounting.


    What equipment will I need to run both? I am doing as much research I can on the topic and plan on pulling the trigger once I have everything set. I also plan on adding a second battery and a battery isolator to cutdown on electrical noise.
    You can buy coax switches, but if you want to switch between antennas from your apartment, you will need two coax lines out to your vehicle.
    If you upgrade to General class, you will have voice privileges on all HF bands except thirty meters. Of course, in a true emergency, even unlicensed persons can transmit using any frequency or mode.

    Ben

  3. #3

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    HF mobile is hampered by the antenna systems, which for lower frequencies than 28MHz are always pretty inefficient. Radios that claim to be HF and VHF/UHF tend to mean just one or two HF bands. For more reliable comms you need to be able to use the most appropriate HF band as propagation changes constantly, so a separate HF transmitter and then VHF/UHF one are by far the best option. You are spending lots and getting little, because HF mobile is almost a hobby in itself. It is NOT a plug and play option, it needs considerable skill and experience to use effectively. Your car will also look very silly with the good HF antennas fitted. Subtle they are not!

  4. #4

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    Thanks for the advice guys! I may not have been clear before and my apologies, but my homestation will be strictly the vehicle, no coax's will be run to the apartment since I have to park across the street but that is a good idea in itself. I was thinking of doing some sort of HAM override switch in the vehicle to keep the system running while the key is turned off in order to run the unit and somehow turn the truck into a repeater for a handheld unit. Does anyone have any information on how that can be done?

    For the HF bands, I am taking my General class next month which should give me some experience, but from the sounds of it perhaps I should work on VHF/UHF first until I become more comfortable with that then work on installing an HF antennae down the road. One option I have, and since the HF will be used for emergencies primarily, is attaching the HF antennae to my utility trailer and then having a coax extension to the rear of the truck for connecting to HF when I am hooked up to the trailer, since the HF antenna’s look extremely conspicuous and not something I would want to have on my truck 24/7. So I guess what I need next is a VHF/UHF/HF transceiver for future compatibility. I am looking into a Yaesu FT-8900R and a Yaesu FT-857D. Is there any difference between the two besides the small footprint? And what antennae is recommended for VHF/UHF? I see that there are quad band antennaes available, does that mean 6m and 10m compatibility with 2m/70cm? Is it better to get two separate antennas for potential HF in the future? Sorry for so many questions, I have been trying to wrap my head around all of this!

  5. #5

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    Alternatively, would a GPS EchoLink enabled transfeiver be a substitute for HF during a grid down scenario? Or am I better off with a GPS enabled phone or HF?

  6. #6

    Join Date
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    A VHF/UHF radio with or without EchoLink will be near useless in a real emergency if you think you can reliably use repeaters. Repeaters will only have back up power for a few days at most. Since you are in the Keys long range means mainland to me. For HF you could easily contact Florida with 75m NVIS antenna and 50 watts. A 80m dipole needs to be only 10 n- 15' off the ground.

    However there is no need to go HF unless you plan to upgrade and then start using HF on a regular basis. This is where the operational knowledge comes from. Having a radio, knowing how and when to transmit will come as your time on the air increases.

    Good luck.
    Last edited by W8MLS; Sun 19th Nov 2017 at 21:10.

  7. #7

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    Quote Originally Posted by W8MLS View Post
    A VHF/UHF radio with or without EchoLink will be near useless in a real emergency if you think you can reliably use repeaters. Repeaters will only have back up power for a few days at most. Since you are in the Keys long range means mainland to me. For HF you could easily contact Florida with 75m NVIS antenna and 50 watts. A 80m dipole needs to be only 10 n- 15' off the ground.

    However there is no need to go HF unless you plan to upgrade and then start using HF on a regular basis. This is where the operational knowledge comes from. Having a radio, knowing how and when to transmit will come as your time on the air increases.

    Good luck.
    Not altogether correct... There is an increasing trend to make repeaters completely independent of the power grid through the use of solar power. For instance, my club has two repeaters running totally on solar power with back-up batteries for nighttime and days when there is no sun. The system has been in place for several years and functions flawlessly.

  8. #8

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    Quote Originally Posted by K6CPO View Post
    Not altogether correct... There is an increasing trend to make repeaters completely independent of the power grid through the use of solar power. For instance, my club has two repeaters running totally on solar power with back-up batteries for nighttime and days when there is no sun. The system has been in place for several years and functions flawlessly.
    there are more today than there used to be that utilize batteries and solar power, but they are still few and far between and would still be useless for anything other than the range of the individual repeater... with the grid down, there will not be any linking...so grid down, emergency circumstance, HF is still the most viable, if not 100% dependable means of communication...

  9. #9

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    Sep 2015
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    133

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    I wonder how well repeaters / Echo Link worked in Puerto Rico after the hurricane. I could be wrong but betting it did not help much. I heard VHF/UHF was used for command and control. Experienced ops went to assist. HF was used for mainland communication


    Point is you should not rely on infrastructure when chips are down. 99% of reliable comm can be had by HF NVIS.

    80 Meters NVIS is easily doable.
    Last edited by W8MLS; Wed 22nd Nov 2017 at 20:29.

  10. #10

    Join Date
    Dec 2008
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    1,655

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    I read on QRZ that a General Operator stayed on Key West during the hurricane and after the main storm had moved northward he got on 40 m to pass traffic between Key West and the main land of the United States for his neighbors to let their love ones know that they survived the hurricane. I believe the ham had Battery Back Up for his power source for the transceiver in his home. The use of a 2 m or 70 cm repeater would be useless for this kind of a disaster considering the small RF footprint / coverage the repeater could only provide ... maybe 25 to 30 miles maximum whereas 20, 40 & 80 m has a range of 500 to 1000 air miles.

    Dan
    WA9WVX

  11. #11

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    Quote Originally Posted by Obed View Post
    there are more today than there used to be that utilize batteries and solar power, but they are still few and far between and would still be useless for anything other than the range of the individual repeater... with the grid down, there will not be any linking...so grid down, emergency circumstance, HF is still the most viable, if not 100% dependable means of communication...
    Most, but not all, linking systems are now internet based, mostly because it's convenient, doesn't require a lot of infrastructure and is cost effective. Some repeater systems, however, are still linked using direct radio links. We have a system here that links four repeaters from the Laguna Mountains east of San Diego to the White Tank Mountains just west of Phoenix. They are interconnected with direct UHF links. The system is heavily used by desert dwellers, off-roaders and campers.

  12. #12

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    HF

    Sent from my SM-G935P using Tapatalk

  13. #13

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    Just an antenna comment: I run a 10 meter mobile with 200 watts and use a (permanently installed) shortened K40 with good results.

  14. #14

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    First, welcome to the hobby! Second, good luck on General. Now to the meat of the subject...
    First, buy all of the radio you can afford right off the bat. If you really want to utilize HF, then maybe check into a "shack in the box" like a TS-2000, FT-991a, or an IC-7000. Next, get a good antenna like a GP-3 Comet or similar for VHF/UHF and get it up in the air. Then look at your options for HF antennas. So many hams run amplifiers on HF when a great antenna would do the same. A Chameleon Hybrid with a vertical whip will get you NVIS capability from a 6' tripod. There are many options so do the research. Don't do as I have done and spend a fortune trying to find a perfect radio because it does not exist. Find one that has the features you want, and don't skimp on an antenna, and you'll do well.
    Another issue is using vehicle power. You'll be okay for an hour or two on VHF/UHF, but when you start running 100 watts on HF SSB and pulling 30-32 amps out of your battery, it'll go down quickly.

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