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Author Topic: Can I trust used equipment? Trying to build a manpack.  (Read 309 times)

KF0AGC

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Can I trust used equipment? Trying to build a manpack.
« on: December 21, 2022, 06:07:28 AM »

I'm a little new to the hobby.  I've had my tech license for about 2 years, but have really only used cheap HTs around the rural property my family owns.  Not having any cell coverage down there, and the cheap GMRS handhelds didn't have enough range to talk drove my Dad and I to start using ham.  Anyway, both my Dad and I would like to put together a manpack type of mobile radio.  I'd like to have more than just 2m/70cm because I'd like to progress into HF.  I'm beginning to realize that every radio I'm interested in has been discontinued (FT-857D, IC-706, IC-7000, FT-8900R).  I know the FT-991A is portable, but it is too big for bag I have (PRC-117 radio pouch) with the armoloq frame on it, which I'd like to have on any of the radios I get.  It is also more than I can afford right now. 

Anyway, how well do these radios hold up over time.  I know the FT-857D is prone to zebra stripes, but what else should I look out for on any of the radios listed above?  Does anyone have any other suggestions for at least a quad-band radio?  I know TYT makes a clone of the FT-8900R, but I've read about some QC issues which has scared me away from them.

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K5LXP

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #1 on: December 21, 2022, 06:30:38 AM »

What are your communication goals?  Is it "everything" or are you primarily interested in portable HF?   Is this "transportable", moving the station from location to location or do you have aspirations of HF manpack portable?  A V/U "manpack" will solve few problems over using an HT, other than making you tired carrying it around.   OK if the radio you choose covers V/U but I wouldn't make that a primary choice.

I really enjoy operating in the field, from Field Day like setups, backpack QRP, to satellite.  There's a lot of operating possibilities away from home so narrowing those choices down a bit will help you identify some solutions.

Mark K5LXP
Albuquerque, NM
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US7IGN

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #2 on: December 21, 2022, 06:51:47 AM »

I have had an used ICOM IC-706mk2g (I think I am third owner) for many years and am happy with it when I use it outside the city https://www.us7ign.com/?cat=13. But I had to fix it. My friend bought an Yaesu FT-857 and we had to change filters https://www.us7ign.com/?p=2108. Any old radio may need attention. But at the same time you can learn how to repair them. Don't forget about narrow filters for them. Now I would probably buy Yaesu FT-891.
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KF4HR

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #3 on: December 21, 2022, 07:04:00 AM »

Sounds like you're looking for a portable light weight rig that covers HF thru UHF, for portable and perhaps a shack environment; basically an all-in-one solution.  Some of the discontinued equipment you mentioned has been superseded by a different model.  Two examples come to mind, the Yaesu FT-891 and ICOM IC-7100.  These two rigs offer the frequency range you're looking for and also have the ability to run up to 100w (on most of its bands), and also they have the ability to turn down the power to QRP level for more local use (and provide longer run time for backpack use).  These rigs would work well as both a backpack, shack, or mobile environments.  Another option that covers HF thru UHF is the ICOM IC-705, although this is a QRP rig, so if you want to eventually run HF, you may want to buy an amplifier for it.  Odds are, you may find that QRP on HF many times will not be enough power (particularly when you're new to HF), so having the ability to run at least 100 watts can be very helpful. 

As for trusting used equipment, most (not all) individuals selling used equipment realize their future reputation is on-the-line every time they sell used equipment because many websites allow buyers to leave transaction feedback, outlining their transaction experiences (good or bad), so it's a good idea to look up the call sign of the person and check any feedback they may have.  Another good thing to do is to contact the seller on the phone and ask a series of questions to find out how the equipment was used, if they are the first owner, are there any issues or physical damage, repair history, etc, etc.  This will give you an idea of what condition the equipment is actually in, how it was treated, and generally how dependable the unit is.  Some sellers might offer a refund if the unit does not function as stated, while others sell equipment as-is with no refund, so buyer beware.

If you decide to go down the used equipment route another issue to consider is, if the equipment were to fail after you own it awhile, whether or not the manufacturer still provides repair support.  It's not uncommon for manufacturers to drop repair and parts support after a rig has been out of production for a number of years.  Some manufacturer websites offer a list of older equipment they still provide repair support for.  It would be wise to check these lists or call the manufacturer directly.

I hope you find this information helpful.  GL.       
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G4AON

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #4 on: December 21, 2022, 07:13:58 AM »

”Manpack” portable might sound like a good idea on paper, but it’s not that practical.

Ideas that work include:
Small 10 Watt portable radios such as the Icom IC-705 which gives you 2m and 70cm as well as HF. The lower power FT-818 is popular too. Useful for parks on the air, or summits on the air.

More powerful 100W radios used with a 20 to 60 Ah battery, lugged around on a cart, or sack trolley, and used with a portable mast, or fishing pole. Look up G4VZV on qrz.com to see his Spanish lakeside operation using this setup. Can give spectacular results if you use a vertical near salt water.

Or operating portable from a vehicle, some quite elaborate setups are possible depending on how enthusiastic you are.

Note, I didn’t mention walking around with your HF radio in a backpack and a mobile whip, possibly trailing a counterpoise wire… yes it “sort of works” but can be very frustrating as your signals are likely to be quite weak.

Hopefully food for thought.

73 Dave
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US7IGN

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #5 on: December 21, 2022, 09:46:21 AM »

Note, I didn’t mention walking around with your HF radio in a backpack and a mobile whip, possibly trailing a counterpoise wire… yes it “sort of works” but can be very frustrating as your signals are likely to be quite weak.
I did it. It was awfully!
https://www.us7ign.com/?p=201

Now I have a full setup in my backpack:
ICOM IC-706MK2G
ICOM AH-4
Delta Loop 80m (80-10 with AH-4)
inv.V 40m
2 el. 20m
Asus Eee PC 1025c
Bencher by-1
RG-8 & RG-174
Battery already has built in my car)
https://www.us7ign.com/?p=1665
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N5CM

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #6 on: December 21, 2022, 10:53:57 AM »

With regard to reliability of used gear, here's what I did for one of my rigs.  I bought used gear from an established ham radio dealer.  The equipment came with a 30-day warranty from the dealer.  I believe a number of the dealers offer this.

Yes, I ended up paying a bit more for a piece of used equipment by purchasing from a dealer, but I figured that I should know within 30 days if the equipment was doing what it should do.

Some dealers offer factory refurbished equipment as well.
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KF0AGC

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #7 on: December 21, 2022, 02:18:43 PM »

What are your communication goals?  Is it "everything" or are you primarily interested in portable HF?   Is this "transportable", moving the station from location to location or do you have aspirations of HF manpack portable?  A V/U "manpack" will solve few problems over using an HT, other than making you tired carrying it around.   OK if the radio you choose covers V/U but I wouldn't make that a primary choice.

We have rural property about 50 miles from as the crow flies from where we live full time.  My parents go down there 50% of their time, but there is no cell coverage.  They can use wifi but we want back up communication that can go that whole distance.  We could use manpacks to do that with VHF via repeaters in the area, but we would like to start playing around with HF to potentially bridge that communications gap without the need of a repeater.  I'd also like something with VHF/UHF that could easily hook into my vehicle and a radio in a manpack configuration could do that. 

Quote from: KF4HR
Sounds like you're looking for a portable light weight rig that covers HF thru UHF, for portable and perhaps a shack environment; basically an all-in-one solution.  Some of the discontinued equipment you mentioned has been superseded by a different model.  Two examples come to mind, the Yaesu FT-891 and ICOM IC-7100.  These two rigs offer the frequency range you're looking for and also have the ability to run up to 100w (on most of its bands), and also they have the ability to turn down the power to QRP level for more local use (and provide longer run time for backpack use).  These rigs would work well as both a backpack, shack, or mobile environments.  Another option that covers HF thru UHF is the ICOM IC-705, although this is a QRP rig, so if you want to eventually run HF, you may want to buy an amplifier for it.  Odds are, you may find that QRP on HF many times will not be enough power (particularly when you're new to HF), so having the ability to run at least 100 watts can be very helpful.

As for trusting used equipment, most (not all) individuals selling used equipment realize their future reputation is on-the-line every time they sell used equipment because many websites allow buyers to leave transaction feedback, outlining their transaction experiences (good or bad), so it's a good idea to look up the call sign of the person and check any feedback they may have.  Another good thing to do is to contact the seller on the phone and ask a series of questions to find out how the equipment was used, if they are the first owner, are there any issues or physical damage, repair history, etc, etc.  This will give you an idea of what condition the equipment is actually in, how it was treated, and generally how dependable the unit is.  Some sellers might offer a refund if the unit does not function as stated, while others sell equipment as-is with no refund, so buyer beware.

If you decide to go down the used equipment route another issue to consider is, if the equipment were to fail after you own it awhile, whether or not the manufacturer still provides repair support.  It's not uncommon for manufacturers to drop repair and parts support after a rig has been out of production for a number of years.  Some manufacturer websites offer a list of older equipment they still provide repair support for.  It would be wise to check these lists or call the manufacturer directly.

You hit the nail on the head for what I'm looking for.  The issue with the FT-891 is I'd like VHF/UHF and that radio doesn't have those frequency bands.  The IC-7100 is discontinued, though in stock most places right now.  The issue I have with that is I can't find protective side rails for the body (which I think is important in a manpack type set up), and I'm not a huge fan of the shape of the detached faceplate.  I may have to get over the design though considering it would meet all my needs. 

Good point on their reputation.  I wonder if a hamfest would be a good way to look for used equipment.  There is one near me in January.  I'd think people wouldn't want their reputation hurt at something like that and hopefully there would be a way to test the equipment to ensure it is working.  I also had thought about parts becoming unavailable like you pointed out.  I could see that being an issue.  I'm also not extremely technical, so I'm not sure how successful I would be repairing anything on a radio that would require opening it up.  I guess I'd be game to try, especially if I had already dumped money to buying equipment. 

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WB6BYU

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #8 on: December 21, 2022, 04:07:52 PM »

I've bought several used radios.  Some worked fine, some needed
repair, and at least one wasn't worth repairing.  The best thing is
to find a local ham selling it (possibly a local club member) and
try it out together beforehand, or looking for a reconditioned
radio from a dealer.

50 miles is a bit of an inconvenient distance, depending on the
terrain between the two locations.  With good outside antennas,
you might get through on 2m simplex if there are no hills in the
way and you can get the antennas up high enough.  Its a bit
out of ground wave distance on HF (although you might get
through on 160m).  Local NVIS propagation will give strong
signals on 40, 80, or 160m when the ionosphere is cooperating,
but not when it isn't.  Higher bands likely will skip over that
distance, unless you get some occasional E-skip.   So it isn't
a "plug and play" solution - it requires flexibility to determine
the best band vs. time of day, season of the year, sunspot
activity, etc.

And, for the lower HF bands that are likely to be open over
that distance, you will probably want a wire antenna in the
trees rather than a whip attached to a packframe as a
traditional "manpack" might imply.  In that case, you just
want a "portable" station that can be moved, but not
necessarily operated in motion.  That makes a big difference
in requirements.

Perhaps the most likely mode would be 6m SSB (or possibly
FM), again depending on antenna height and terrain.  Again,
antennas likely would be relatively fixed rather than operated
in motion.


I would generally suggest splitting VHF/UHF and HF into two
different separate radios.  That allows you talk on the repeater
to each other while you try to get your HF station set up, or to
find what frequency might be open.  A monoband 2m FM radio
is relatively cheap, and it opens you up for more options in an
HF radio.

G4AON

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #9 on: December 22, 2022, 04:47:17 AM »

50 miles can be a difficult distance, as per the last reply.

HF is too far for good ground wave, and not far enough for sky wave. 160m with loaded verticals, or inverted L antennas, with several radials and 100 Watts of SSB will get you 20 to 30 miles easily on ground wave in daytime, 50 miles is probably possible with really good antennas, but not with typical “back yard” ones.

To give you an idea of VHF SSB range, I have daily skeds with a fellow ham at 42 miles on 2m SSB. I use a 6 ele yagi up 32 feet, he uses 2 x 8 ele at a similar height. His elevation is around 430 feet and mine only around 9 feet. There are no significant obstructions between us. Signals are 5 x 9 both ways running 40 Watts. Transceivers are both Icom IC-9700.

Maybe decent beams on VHF with a bit of power, depending on terrain, is the way to go. Sorry it’s not really man pack stuff.

73 Dave
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G4AON

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #10 on: December 22, 2022, 05:17:16 AM »

This website will show you what may work on VHF. It’s free, but you have to register and it’s mainly aimed at coverage to mobiles, but you can input beam antennas at both ends. See:

https://www.ve2dbe.com/english1.html

73 Dave
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KF0AGC

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #11 on: December 22, 2022, 05:56:11 AM »

50 miles is a bit of an inconvenient distance, depending on the
terrain between the two locations.  With good outside antennas,
you might get through on 2m simplex if there are no hills in the
way and you can get the antennas up high enough.  Its a bit
out of ground wave distance on HF (although you might get
through on 160m).  Local NVIS propagation will give strong
signals on 40, 80, or 160m when the ionosphere is cooperating,
but not when it isn't.  Higher bands likely will skip over that
distance, unless you get some occasional E-skip.   So it isn't
a "plug and play" solution - it requires flexibility to determine
the best band vs. time of day, season of the year, sunspot
activity, etc.

And, for the lower HF bands that are likely to be open over
that distance, you will probably want a wire antenna in the
trees rather than a whip attached to a packframe as a
traditional "manpack" might imply.  In that case, you just
want a "portable" station that can be moved, but not
necessarily operated in motion.  That makes a big difference
in requirements.

Perhaps the most likely mode would be 6m SSB (or possibly
FM), again depending on antenna height and terrain.  Again,
antennas likely would be relatively fixed rather than operated
in motion.

We thought with a good radio and perfect conditions 2m MIGHT be good without repeaters, but I don't think we have perfect conditions lol.  Our houses where we live full time are higher in elevation than the rural property and there are some hills in the way that could effect the signal.  I'm interested to try 2m SSB and 6m FM & SSB and see how it goes.  I appreciate the info on the other bands as well.  I have a little experience with NVIS from my time in the Army, but that seems like it was ages ago and will take some practice. 

This set up would also be our SHTF set up so our thoughts are unless we are stationary we would use 2m/70cm on the move (maybe 6m if we had the right antenna set up).  Once we could get stationary and set up an OP, we would work HF if we felt the need.  For that we would use the wire antenna in a tree. 


Quote from: G4AON
To give you an idea of VHF SSB range, I have daily skeds with a fellow ham at 42 miles on 2m SSB. I use a 6 ele yagi up 32 feet, he uses 2 x 8 ele at a similar height. His elevation is around 430 feet and mine only around 9 feet. There are no significant obstructions between us. Signals are 5 x 9 both ways running 40 Watts. Transceivers are both Icom IC-9700.

Maybe decent beams on VHF with a bit of power, depending on terrain, is the way to go. Sorry it’s not really man pack stuff.

I've heard good things about 2m SSB in terms of range.  I've also heard less people use that so it may be a little more "secure", so I'm pretty interested in trying it out.  Coming up with a portable antenna solution for that would take more of a deep dive, but I don't mind researching. 

Thank you both for the information. 

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KF0AGC

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #12 on: December 22, 2022, 08:45:37 AM »

This website will show you what may work on VHF. It’s free, but you have to register and it’s mainly aimed at coverage to mobiles, but you can input beam antennas at both ends. See:

https://www.ve2dbe.com/english1.html

73 Dave


Very interesting site, so thank you for sharing.  Can someone confirm my thought process on some of the performance data?  I'll list it below, but just playing around I put in stats for average of the radios/antennas I've looked at.  Am I correct to assume if there is a negative value for the received signal then this is saying it won't make that distance?

Distance                                                   80.575   km
Precision                                                   40.3           m
Frequency                                                   144.000   MHz
Equivalent Isotropically Radiated Power   99.763   W
System gain                                           164.51   dB
Required reliability                                   70.000   %
Received Signal                                          -144.57   dBm
Received Signal                                           0.01           μV
Fade Margin                                               -31.55      db
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WB6BYU

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #13 on: December 22, 2022, 11:07:57 AM »

6m often works better than 2m in hilly country, as signals
tend to work their way over hills a bit better.  We saw that
on some local government networks, where the repeaters
on 155 and 455 MHz had pretty good coverage, but 43 MHz
simplex could get through from rough spots when the others
couldn't.

For VHF/UHF (including 6m), plan on using beams pointed in
the desired direction for some added gain.  You may need to
run some tests to see how high the antennas need to be as
well.  Sometimes you can get around a hill via reflections or
other stray paths.  And height can make a big difference.

That's one reason why a "manpack" station might not be
the best option.  If you are using a beam antenna at 30 too
50' at one or both ends of the link, that's a bit difficult to
carry around on your back and operate in motion.  But not
difficult for portable operation:  a set of the military camo
poles can be set up as a 32' mast relatively quickly, and
used to support a VHF beam and/or HF wire antenna.

Also, pay attention to polarization.  Horizontal polarization
isn't as convenient for mobile operations, but can give
better results over fixed terrestrial paths than vertical
polarization.
« Last Edit: December 22, 2022, 11:10:02 AM by WB6BYU »
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G4AON

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Re: Can I trust used equipment? Trying to build a manpack.
« Reply #14 on: December 22, 2022, 11:35:57 AM »


Received Signal                                          -144.57   dBm
Received Signal                                           0.01           μV
Fade Margin                                               -31.55      db
You need a much stronger signal than 0.01uV, that is not workable. 2 to 3uV is probably the very minimum workable signal for regular contacts, you need a margin to allow for fading (it happens on VHF) and to allow for QRN from electrical devices, etc.

73 Dave
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