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VK Amps KM3KM Sampler Comparison

Posted: Sat Feb 10, 2024 9:38 pm
by KD1GA
both samplers.jpeg
both samplers.jpeg (3.26 MiB) Viewed 13111 times
VK Sampler.jpeg
VK Sampler.jpeg (2.94 MiB) Viewed 13111 times
KM3KM.jpeg
KM3KM.jpeg (3.05 MiB) Viewed 13111 times

Re: VK Amps KM3KM Sampler Comparison

Posted: Sun Feb 11, 2024 12:04 am
by w-u-2-o
-65 dB is too much. The -55 dB of the VK unit is perfect at the legal limit.

Re: VK Amps KM3KM Sampler Comparison

Posted: Sun Jun 09, 2024 1:27 am
by RobB
signal levels aside one unit looks to be professionally made the other a junkbox special.

Re: VK Amps KM3KM Sampler Comparison

Posted: Sun Jun 09, 2024 11:46 am
by Dan
I purchased the VK model specifically because of the surface mount resistors. This keeps the traces short to them. And as Scott says, -55 dB is perfect, at 5 watts or 1500 watts. I never have to add additional attenuation.

73, Dan

Re: VK Amps KM3KM Sampler Comparison

Posted: Tue Jun 11, 2024 11:10 am
by Dennis
That is not a Comparison,

have been using and sending and recommending VK-AMPS sampler for years, stable and in some instances, works better then the Internal OM amp fitted unit, plus other amp manufacturer's factory fitted sniffers,

I have tested VK-AMPS samplers with
SPE, 1.3,1.5, S2/S3, SPE 2KFA
VK-AMPS air cooled and water cooled,
THP
FL-7000
9500
A87A
8410
AL-1500
AL-1200
AL-82
AL 800H
ACOM 1500
Acom 2100
Acom 2000
using
ANAN 200D, ANAN 7000 DLE MK II, ANAN G2 radios ( with Excellent reports from HERMES LITE users in EU using the VK-AMP sampler,

well made stable, value for money,
his amps a Beasts, the Water Cooled 2 X 1K80 65V is a BEAST on Steriods after sniffing angle dust,

Cheers
Dennis vk4sx

Re: VK Amps KM3KM Sampler Comparison

Posted: Fri Jun 14, 2024 8:20 pm
by w9ac
Thankfully, RF is visually blind. Some of best performing devices I've measured are aesthetic nightmares (and vice versa).

I've no idea about the KM3KM sampler but it's likely a local project from Miami. My understanding is the Lux and Mercury III amps are designed by RZ1ZR (not just the LCD display) and assembled by KM3KM in Miami, despite all the PC board nomenclature that suggests otherwise.

Paul, W9AC

Re: VK Amps KM3KM Sampler Comparison

Posted: Mon Jun 17, 2024 10:12 pm
by rdwing
w9ac wrote:Thankfully, RF is visually blind. Some of best performing devices I've measured are aesthetic nightmares (and vice versa).

I've no idea about the KM3KM sampler but it's likely a local project from Miami. My understanding is the Lux and Mercury III amps are designed by RZ1ZR (not just the LCD display) and assembled by KM3KM in Miami, despite all the PC board nomenclature that suggests otherwise.

Paul, W9AC


I don't think so. The same sampler could be found on ebay for $30 from China, although now I only see the same units claiming made in USA.
I would not want to send legal limit through that.

The VK3AMP sampler is beautifully constructed, with actual test and validation data available. Everything Onder makes is impressive. That's the sampler I recommend to folks.

I would also not recommend the cleanRF sampler, if only because the signal is run through a variable pot and does who knows what to it, with the added risk of blowing up your ADC.

Re: VK Amps KM3KM Sampler Comparison

Posted: Sun Jun 30, 2024 11:57 pm
by RobB
w9ac wrote:Thankfully, RF is visually blind. Some of best performing devices I've measured are aesthetic nightmares (and vice versa).

I've no idea about the KM3KM sampler but it's likely a local project from Miami. My understanding is the Lux and Mercury III amps are designed by RZ1ZR (not just the LCD display) and assembled by KM3KM in Miami, despite all the PC board nomenclature that suggests otherwise.

Paul, W9AC


If you take a look at RZ1ZR website. specifically his amp control boards I think you may change your mind. He has a great aesthetic look in the display and his firmware does a fine job but his own hardware comprises a bunch of cheap modules soldered to a carrier board, lacking any kind of integration. He supplies the firmware to various boutique amp makers KM3KM, Vk-Amps, EB104 and soon Apache labs. In each case the makers have developed their own control boards around his firmware. To compare his hardware implementation to the "hardware guy's" efforts the difference is chalk and cheese.

Re: VK Amps KM3KM Sampler Comparison

Posted: Mon Jul 01, 2024 1:36 am
by w9ac
Dig deeper.

I found the LPF board designed and manufactured by RZ1ZR, saved by archive.org in 2018. It no longer appears in the same form and layout as shown on his current website.

Now compare it to the Mercury III LPF board as shown by AE5X on his blogspot.

Both images attached.

The topic is about the RF sampler. I'm simply questioning its origin as well as the amplifier circuit boards. I've no issue claiming something is "designed and manufactured in the U.S.," provided it actually is.

Paul, W9AC

Re: VK Amps KM3KM Sampler Comparison

Posted: Fri Jan 17, 2025 10:41 pm
by vu2mb
w9ac wrote:Thankfully, RF is visually blind. Some of best performing devices I've measured are aesthetic nightmares (and vice versa).

I've no idea about the KM3KM sampler but it's likely a local project from Miami. My understanding is the Lux and Mercury III amps are designed by RZ1ZR (not just the LCD display) and assembled by KM3KM in Miami, despite all the PC board nomenclature that suggests otherwise.

Paul, W9AC


Yes, I too believe RZ1ZR is the designer, and both he ( he was selling it to Russians and nearby countries) and Kenny sold the Mercury III until the Ukraine-Russia war broke out and the boycott of Russia began. Some hams pointed out that Mercury was made by Victor, which Kenny denied, claiming that even the firmware was not Victor's creation.

It seems some sort of agreement was reached between them, as Victor removed the Mercury III from his website, although he continued selling components like the PA board, a slightly modified LPF, and the controller. I purchased those boards from him as a precaution.

I bought the Mercury III PCBs from Kenny and was instructed to purchase the firmware from Victor. I assembled my Merc III and still using it. Spare PCBs are compatible and I am keeping them for a rainy day.

73
Bhanu
VU2MB

Re: VK Amps KM3KM Sampler Comparison

Posted: Fri Jan 17, 2025 11:31 pm
by w9ac
vu2mb wrote:
I bought the Mercury III PCBs from Kenny and was instructed to purchase the firmware from Victor. I assembled my Merc III and still using it. Spare PCBs are compatible and I am keeping them for a rainy day.

73
Bhanu
VU2MB

Thank you, Bhanu. Despite claims made in the owner's manuals, I believe we can safely assume that the Mercury line of amps are not designed in the U.S.

Paul, W9AC

Re: VK Amps KM3KM Sampler Comparison

Posted: Sat Jan 18, 2025 4:40 am
by RobB
on my home brewed sampler I used a flange mount male 259 and it screws directly to the antenna socket. The result is a secure connection and 1 less patch cable required.