Friday, December 7, 2018

Hardrock-50 on order

Phew! I almost spent $1200 on a 100W amp - what was I thinking?!

With that order now cancelled I've been roaming the web for an alternative to the Elecraft KXPA-100. Here were the contenders (it's a short list):

Juma PA-100D kit - Chinese copy


Juma PA-100D - the big brother of this amplifier was recently ordered by DXpeditioner Tom KC0W. After 4 months, he still likes it and plans on using it with his KX3 (which will drive it to a full kw) on a DXpedition to YS (El Salvador to non-DXers) next month. But Juma's website lists the PA-100D as "not in stock". Unfortunately, they don't respond to requests for info on when it may again be available. This leads us to:

Chinee Copy of PA-100D - at what point does it become ethical to buy these pirated copies? Never? When the original manufacturer ignores its would-be customers? To many hams, ethics never enters the sphere - only dollars, and the cheaper supplier wins. FWIW, this eBay offering is an already-built version of the Juma kit.

And the winner is:

Hardrock-50 - this 50-watt amp kit has a long and stellar history. Just try to find a negative review about it. It has 3dB less output than the others ("half an S-unit" in CB-speak) and costs 3.5dB less than the Elecraft amp.

A $30 option allows this amp to automatically follow band switching commands from a KX3 and a built-in autotuner is available. Total price with KX2/KX3 compatibility, autotuner and QSK option - $557.

The amp itself, and the build process, is extensively documented and has an active forum of satisfied users.

I've known about this amp for a long time and yet never considered it due to the 50W output. It just didn't seem worth it to go from 10 watts (KX2, Anan-10e) to 50 watts (7dB).

So why now? A few reasons:

  • FT8 - my plans for an amp in this power range are to allow my Anan-10e to be a dedicated digital station. Even with the Flex (with KPA-500 available) I've almost always limited my output to 40-50 watts on FT8 and have never needed more, even when DXing on 80 meters with that mode.
  • Portable ops - from time to time I like activating parks...or just going afield for no reason at all and operating among the deer, birds and skeeters. For portable ops, on a battery, 50 watts from an amp will give me more time than a 100W amp. True, I could turn a 100W amp down to 50 watts but if I'm going to do that, why pay the extra premium for a 100W amp?
  • Compatibility with simple QRP rigs that don't have a KEY OUT jack. Although the Hardrock-50 has a PTT (KEY IN) jack it also has a carrier operated relay for keying. This means that it can be used with rigs like the Norcal 40a, Hilltopper, HW-9 and other QRP rigs that don't have the PTT output that would be required in order to key the other amplifiers mentioned here.
  • I'm spending $650 less than if I'd bought the E amp. With that savings I could fly to Calgary, stay at an AirBNB and activate (and photograph!) Banff-Jasper during the upcoming CNPOTA. That's significant - for the money I'm saving, I can fly to somewhere exotic-to-me and use my new amplifier that I built myself...if I'm willing to settle for 50 watts instead of 100...which I am. AG6QR has a more detailed comparison of this amp with the E amp here.

The Hardrock-50 with all options is now on its way to me .
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3 comments:

Tim N9PUZ said...

I had a Hardrock-50 when I used an FT-817. It's a good, solid product. You will enjoy it. Sadly these days aging eyes make it tough for me to build kits otherwise I'd have been tempted by another one.

John AE5X said...

Hi Tim,

I bet if you posted to the forum you'd find a number of people willing to build one for you for a reasonable fee. t's good to see all the positive feedback from those who own this amp and makes me feel like I made the right choice in buying it over any of the other possibilities. And I think some of my old QRP rigs will be put to use again since the HR50 doesn't need a Key In signal to activate it.

Thanks for your comment Tim and 73,

John AE5X

John AE5X said...

HR50 forum:
https://hobbypcb.com/forum/8