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Author Topic: Best Amplifier for the Yaesu FT 817 ND  (Read 5796 times)
KC8VWM
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« on: July 18, 2006, 07:21:24 PM »

I am looking for opinions and personal experiences for the best amplifier used with the Yaesu FT 817 ND QRP backpack rig.

What I am specifically looking for is a small compact sized amplifier yet it should have the ability to perform over a wide bandwidth of radio spectrum using only 5 watts or less as the amplifiers input.

Maximized output power is not as much as a factor as portability and band coverage capability especially for the purpose of portable emergency communications work.

Both HF and VHF/UHF combo amplifier ideas / suggestions, personal experiences would be a great help.

Think portable and think emergency. Smiley

The floor is open and ANY suggestions are most welcomed and most appreciated.

My Best,

KC8VWM
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RobertKoernerExAE7G
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« Reply #1 on: July 18, 2006, 07:55:06 PM »

http://groups.yahoo.com/group/FT817/
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K5LXP
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« Reply #2 on: July 18, 2006, 08:45:16 PM »

The best solution I can think of is to sell the 817 and buy and 857 or 897.  By the time you buy all the extra stuff you need to marry one or more amps to the rig and consider the extra bulk and weight, I'll bet you're in it for more than an 857 is out of the box.  Yeah, you might pay a slight additional RX power requirement but that would be easier to satisfy than dealing with extra equipment and cables.  By carrying all this extra stuff you've negated the one advantage of having an 817 to begin with.

Mark K5LXP
Albuquerque, NM
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KC1QF
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« Reply #3 on: July 19, 2006, 07:44:02 AM »

I also have an FT-817 (and an IC-703) and bought a KL203 amplifier from RMI Italy that uses 4 MOSFETS, runs at 13V, operates from 11MHz to 28MHz and puts out about 30/40W from 5w (or 60/80W from 10W - with my IC-703). It cost me about $68 from ebay. It actually works pretty well. It uses a design that was first presented in QST and also repeated in the RF amplifier ARRL book).

I like the FT-817 but 2.5W/5W on SSB is not very useful (it's great for VHF/UHF however) so a bit of power helps. I also have a 400mA solar panel feeding a 7A 12V battery during the day.

The 12V/7A battery is very useful for the purpose and all the equipment fits within a wide fanny pack (I got mine from www.MEC.CA when I was in Canada).
Hope this helps,
73s,
Peter

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K8AG
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« Reply #4 on: July 19, 2006, 10:12:47 AM »

I traded up to an 857D.  I can crank it down pretty far for QRP and it isn't much worse on batteries than the 817.

No extra wires and connectors either.

My 2 cents.

73, JP, K8AG
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WB2WIK
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« Reply #5 on: July 19, 2006, 10:15:34 AM »

I agree with Mark's "solution," of trading the FT-817 in on an FT-857.  Not much difference in cost, and the 857 runs 100W on HF, as well as substantially more power on 6m, 2m and 70cm than the 817 does.  It's also just slightly bigger and heavier than the 817, but nowhere near as big and heavy as using separate outboard amplifiers plus the 817ND.

The RM Italy amp referenced is a good deal financially but a dirty amp that's illegal for sale in the U.S. for good reason.  Note it's optimized for the CB band, and doesn't cover 40m or below, at all.  These are the bands where the most power is usually required, because portable antennas are much more of a compromise than on the higher frequency bands.

I'd do an 817-857 swap, shell out a few extra bucks, and have it all in one legal, licensed, legitimate package.

WB2WIK/6
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K7VO
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« Reply #6 on: July 19, 2006, 12:47:02 PM »

I disagree with the idea of selling the FT-817ND and replacing it with an FT-857D.  You lose the portability and low power consumption when you want it.

Tokyo Hy-Power makes an outstanding amp for the FT-817, the HL-100BDX.  It is not heavier than an FT-857D, is designed for the ham market and is clean, and it will give you >100W on 80m-6m.

Talk to some of the people on the Tokyo Hy-Power reflector who have bought these.  See:  http://groups.yahoo.com/tokyohypower

As for the legality of importing these amps please see this post from early 2001 where members of the FT-817 reflector queried the FCC: http://groups.yahoo.com/group/FT817/message/1747

Here is the relevant part:

"I have now had FCC Rules 97.315 and 97.317 clarified by the FCC. The following summarizes what I was told.

97.315 (b) preamble is really addressing manufacturers rather than hams. Exceptions are provided in 97.315 (b)(1)-(5). The interpretation is that we (hams) may use or operate uncertified external RF amplifiers as defined in this section. We may also build them ourselves except from a kit. It is noted that 97.317 does not apply in this case and 97.315 stands separately.

The matter of THP amplifiers can be stated as (i) THP can not legally import to the USA since the little amps can not pass 97.317, (ii) Customs can confiscate them, and (iii) hams CAN use them if they can get them. Once in the "amateur system," 97.315 (b)(4)&(5) apply and allow legal sale between dealers and hams. It is of course the amateur's responsibility to be sure the amp meets the emission requirements.

[...]

Bottom line is that if you can acquire a THP or like amp, you can use it. The rules are to control (primarily) manufacturers, not hams it turns out. Good news for those wanting more power."

I am not aware of anyone who has had even the slightest problem importing from THP.

The official Tokyo Hy-Power website is at:  http://www.thp.co.jp/thp%20hp%20Eng/amateur_eng/hf_eng.htm

Most hams who import THP amps are now reporting delivery in 3-4 days.  The HL-100BDX is absolutely the best solution for you.

73,
Caity
K7VO
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NORTHCOUNTRY
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« Reply #7 on: July 20, 2006, 07:06:06 AM »

You can build a linear for HF pretty easily for about $150.  I've built linears but have found that these home brew bare bones solid state linears have pretty bad spectral purity and bad harmonic suppression.  Otherwise they do work good!  

It is more complicated to build an amp that would do both HF and VHF.  I've been studying the 35 watt amp designed by the Falmouth Amateur Radio Assoc. and the design seems pretty good with several output filters for different bands.  Of course it would be a pain to have to switch bands on the amp also.  That is why it would obviously be just easier to get the 100w transceiver to begin with.

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KC8VWM
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Posts: 3119




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« Reply #8 on: July 20, 2006, 08:00:42 AM »

Thanks for the suggestions so far.

Some very constructive considerations have been presented that I have taken into serious consideration. Some of the comments that have impressed me are as follows:

A) Mark K5LXP

“By carrying all this extra stuff you've negated the one advantage of having an 817 to begin with. “


B) Peter KC1QF

“bought a KL203 amplifier from RMI Italy that uses 4 MOSFETS, runs at 13V, operates from 11MHz to 28MHz and puts out about 30/40W from 5w”

C) JP, K8AG

“Traded up to an 857D. I can crank it down pretty far for QRP”

D) Steve, WB2WIK/6

 I'd do an 817-857 swap, shell out a few extra bucks, and have it all in one legal, licensed, legitimate package.

E) Caity, K7VO

You lose the portability and low power consumption when you want it.

Tokyo Hy-Power makes an outstanding amp for the FT-817, the HL-100BDX. It is not heavier than an FT-857D, is designed for the ham market and is clean, and it will give you >100W on 80m-6m.

F) NORTHCOUNTRY

It is more complicated to build an amp that would do both HF and VHF.




Thank you for all your comments so far.

Caity brings up a good point about the FT 817 portability factor although Mark is also right on target in the fact that carrying “extra” stuff around reduces the portability factor.

I have researched idea of trading up as suggested by Steve, JP and others however it appears the 857D has been discontinued. Therefore I may not have this option available to me.

So I am left with only one choice in the matter. It seems if I need more power I need to acquire an amplifier. Perhaps the Tokyo Hy-Power or RM Italy are good choices? I don’t know much about the technical specifications of these amplifiers but I am concerned about their spectral purity as I like to keep a clean ship.

Additional thoughts, suggestions or comments about the direction I should take are most appreciated.

73

Charles – KC8VWM




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WB2WIK
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« Reply #9 on: July 20, 2006, 08:34:03 AM »

FT-857D discontinued?  It is?

I just called HRO and they have it in stock, I could go pick one up this morning.

AES lists it as in stock with a free remote panel kit for $679.99, available as of this morning.

If it's discontinued, that must have just happened and they're still for sale.

Anyway, if you decide to keep the 817ND and go with an amp, I'd recommend the THP way over the RM.  THP makes real, honest amateur radio amplifiers.  That they're not legal for sale in the U.S. doesn't reflect anything wrong with them -- there's just a regulation here that prohibits selling "low drive" HF amplifiers, period.

The RM Italia amp, on the other hand, is a CB amp and junk by comparison.

WB2WIK/6
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KC8VWM
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Posts: 3119




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« Reply #10 on: July 20, 2006, 10:04:48 AM »

Thanks Steve. I didn't know HRO had them in stock apparently I got my information here:

http://www.universal-radio.com/catalog/hamhf/0857.html

Thanks!



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N3OX
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« Reply #11 on: July 20, 2006, 12:00:49 PM »

Yep, original FT857 has been discontinued.

FT857D has not... says so on the left of the page you posted...

73,
Dan
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73,
Dan
http://www.n3ox.net

Monkey/silicon cyborg, beeping at rocks since 1995.
KC8VWM
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Posts: 3119




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« Reply #12 on: July 20, 2006, 02:15:49 PM »

Oh!.. Smiley

Thanks Dan. Guess I missed that.
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K9COX
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Posts: 54




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« Reply #13 on: July 21, 2006, 07:56:10 AM »

Nice little 35-45 watt HF amp kit.

http://www.hfprojects.com/hfprojects/
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