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Reviews For: Yaesu Quadra VL-1000

Category: Amplifiers: RF Power - HF & HF+6M

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Review Summary For : Yaesu Quadra VL-1000
Reviews: 87MSRP: 4000
Description:
Solid-state, automated 1 kW HF/6m linear amplifier
Product is not in production
More Info: https://www.yaesu.com/indexVS.cfm?cmd=DisplayProducts&ProdCatID=102&encProdID=261A83CAF673084AAC58C6801013F76F&DivisionID=65&isArchived=1
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
25874.3
K6BRN Rating: 2023-03-15
A Good but DATED Solid State HF/6M Amplifier Time Owned: more than 12 months.
UPDATED 3-14-2023

SUMMARY: This is a 5-Star solid state amplifier for yesterday and a 4-Star amplifier for today in light of newer products that are half the weight, much smaller, more power efficient and more powerful. Regardless - this is a VERY good HF/6M amplifier. Not something I'd want to lug on a DXpedition, though!

DETAILS: The 1 KW Quadra VL-1000 HF/6M amplifier and it's separate VP-1000 power supply is large and heavy (78 lbs.) compared to more modern and powerful solid state HF/6M amplifiers (like the 1.5 KW Elecraft KPA-1500 which weighs just 39 lbs.). Visually, its looks a lot like a late '80's high end component stereo system tuner/amp, with concealed control buttons and a large but monochrome, low-res LCD panel. It will supply 1 KW PEP (HF)/500W PEP (6M) when running from 240 VAC and up to 500 W PEP on 120 VAC (not recommended). High duty cycle/digital modes should be limited to 500W, per Yaesu. A built-in, motor AND relay driven automatic tuner allows matching of most resonant (~3:1 SWR) antennas at full power. While it has excellent peak/average power and SWR/SWR map readouts, it curiously lacks a PA temperature indicator, other than overheat and fault.

Like the Icom PWM-1, the Yaesu Quadra was an elite solid state amplifier when introduced in 1997/98, and its heavy, no expenses spared, quality build still reflects that.

For anyone considering buying a used Quadra (they were discontinued in 2020) Adam Farson, AB0J, has a great set of web pages on the Yaesu Quadra with a lot of resources, including FAQ's, repair info, operating experiences, etc. (Thanks, Adam!): https://www.ab4oj.com/quadra/main.html

The Quadra design is dated and uses eight (8) MRF-150 transistors in four complementary pairs (hence the name "Quadra") whose outputs feed a fairly lossy combiner tree, and so it's not the most efficient solid state amplifier out there today. Newer LDMOS amps usually eliminate the combiner tree by using a single, higher power complementary pair of transistors, sometimes with both in the same module (looks like a single transistor). But the good news is that the Quadra's MRF-150 transistors are relatively inexpensive and readily available as of 2023, if repairs are needed. In fact, a pair of their close cousins, the VRF-150's, are used in the much newer, 200 Watt Yaesu FTDX-101D/MP.

But as all things Yaesu - the Quadra has a few quirks...

The Quadra should be turned on in a specific 3-step sequence. FIRST: rear VP-1000 mounted MASTER circuit breaker which I just leave ON, SECOND: VP-1000 front panel "hard" POWER switch, then THIRD: VL-1000 front panel "soft" POWER switch. Turn off in reverse order.

If just the VL-1000 soft switch is used to turn the amp off (VL-1000 power supply left ON), then it will actually be in "standby" mode and will periodically "exercise" its relays with a noticeable "clicking" sound. The VP-1000 power supply is also prone to damage from AC mains fault events, so its best to turn it and the VP-1000 off completely, from its front panel 'hard" switch - AFTER shutting the VL-1000 off via its soft switch.

When used with non-Yaesu rigs, the Quadra/VL-1000 requires pushing a front-mounted button to "auto-sense" and move to the correct frequency based on exciter output. But it can be set to follow band moves automatically and instantly via a dedicated control cable with Yaesu (only) rigs. This works fine with the FTDX-101D/MP, FTDX-5000/-3000/-1200, FT-991/991a and many other Yaesu radios.

The VP-1000 has two separate radio control ports (and linked exciter input ports) to allow automatic band switching by Yaesu HF/6M transceivers. But each port has slightly different auxiliary control lines in addition to the band selection lines. Yaesu recommends use of the #2 control and exciter inputs for the FTDX-101D/MP, FTDX-3000/-1200 and FT-991/991A. Unfortunately the amplifier passes through only the #1 exciter input to the #1 antenna output when off, so for any other configuration it must be powered up but disabled for amplifier pass-through.

The Quadra includes a low power mode where final transistor voltage is reduced from 50 VDC to 35VDC. This low power mode improves crossover distortion and lowers power dissipation/heating when running at or under 500W output - great for high duty cycle/weak signal digital modes like FT8.

There is also a switchable 3 dB INPUT attenuator pad that INCREASES required drive by 3 dB (doubles it). This attenuator is intended to allow safe operation of the Quadra with exciters putting out more than 100 Watts (like the 200 Watt FTDX-101MP) by providing more overdrive margin. It's also handy for reducing amplifier power output significantly in one "jump", or for going below 100W output with the amplifier still in line when used with transceivers like the the FTDX-101/-3000/-1200 and FT-991/991A, etc., that have a minimum 5-Watt output level.

A 20 dB OUTPUT attenuator is automatically switched in-line during antenna tuning to reduce interference to other hams. The good news is that it works very well. The bad news is that tuning REQUIRES about 70 Watts of drive from the exciter for successful tuner activation - otherwise it aborts. I put the amplifier in BYPASS mode for antenna tuning just to be safe as 70 Watts of drive can actually OVERDRIVE the Quadra in normal operation, which usually requires no more than 40 Watts drive for full output and forgetting to back off drive after tuning can be problematic. Yet another "quirk"/feature/operating procedure that is not well explained in the manual.

There is no direct temperature readout on the VL-1000 but final transistor heating can be gauged as amplifier gain drops slightly - about 5-10% (it will require more drive for the same output) as the amp warms up. The only indication of temperature beyond this is a warning on the amplifier front panel that the PA is getting too hot, followed by a mandatory, automatic disable if this goes too far. Due to it's size and design, the Quadra has LOTS of thermal mass and heat sink area plus FIVE fans (3 on the VL-1000, 2 on the VP-1000) - so overheating is very unlikely when operated within specs. Still, I LIKE a temperature readout and so installed two thermocouples on the (huge) VL-1000 heatsink, leading to an external meter, just to keep an eye on things.

Despite the number of fans, the amplifier is pretty quiet, emitting a slightly louder and periodic "Whoosh!" when transmitting for a while. You KNOW when the Quadra is working hard from the tone of the fans, but it's never obnoxious. It's certainly quieter than my Elecraft KPA-500 at 500 Watts out in back to back digital QSOs (but I really don't mind that fan noise, either).

After four years of (very happy) intense use on SSB and digital modes one of the MRF-150 transistors failed and was replaced (by John Stanford at Island Amplifier in Placentia, CA - GOOD JOB, John!). I had run the Quadra with FTDX-1200, -3000 and FT-991 radios with resonant antennas ranging from a Cushcraft/MFJ A3S Yagi (now DEAD), Mosley TA-33-MW/40M (working just fine), to a an EFHW-8010-2K end-fed wire (great to fill in the band gaps on the Mosley). One of these antennas suffered an intermittent insulation breakdown at 500 Watts, and this apparently lead to amplifier damage before the protection circuits kicked in. Many amplifiers are subject to this same failure cause/effect so I do not fault the Quadra for this.

I'm currently running the Quadra with an FTDX-101MP and am rediscovering the pleasure of using it - AFTER running my backup amp for a while - an Elecraft KPA-500/KAT-500 amplifier/tuner combo.

The KPA-500/KAT-500 combo is a small fraction of the Quadra's size and weight, is more power efficient, runs happily off of 120 VAC, can seemingly run at 500 W on FT8 all day in back to back QSOs (but with significant fan noise), has no visible "gain droop" when hot and automatically goes into bypass mode (up to 200W "through power") when OFF. Also, the KPA-500 status panel can display finals temp continuously in 1C increments. Effectively, the relatively tiny and convenient KPA/KAT-500 can run FT8 QRO just as well as the super-sized Quadra.

But the Quadra CAN support SSB and CW at 1 KW, one (Yaesu) S-unit (3 dB) greater than the 500W KPA-500, just by pressing a button, and this CAN make a significant difference on those modes.

The Quadra also has two separate and switchable exciter RF input ports and two control ports to go with them ( the KPA/KAT-500 has just one). It has FOUR switchable antenna output ports (KPA/KAT-500 has 3). The relatively slow built-in motor + relay driven tuner is a throwback to yesteryear but seems to handle all of my (resonant) antennas across their respective bands without trouble and has quite a few memories to speed things up.

At 1KW out on SSB some microphonic noise can be heard from the Quadra VL-1000, but this does not seem to affect output signal quality.

Overall, the Quadra is a "tried and true amplifier" that has stood "the test of time" well, but has a few small issues, mainly due to it's dated design: Size, weight, power efficiency and lack of finals temp readout.

Regardless - If you have the space, 240 VAC outlet and a strong bench (and back!) to support it, the Quadra is a pleasure to use. What it does, it does VERY well. And so I've put it back in operation and put the KPA-500/KAT-500 (a GREAT combo) next to it, on "STANDBY".

Best Regards,

Brian - K6BRN
LU9DD Rating: 2022-11-03
just great !! Time Owned: more than 12 months.
1.2k in a second with no blowers noise or rellays. Working it with a FT 1000MP MARK V the band data works great, no more problems with high voltage, mistaken bands or antennas, all the possible protections working great, and good by to lamps each time more difficult and expensive to get from CHINA factories.
It simple push pull 8 MRF150 low cost transistors makes easy to replace just in case (will not ) on the contrary to the new 1 transist plenty of failures and with no soport. I LOVE IT !!!! A war tank !!!
K9OM Rating: 2021-03-29
Excellent Amplifier! Time Owned: more than 12 months.
I've owned Yaesu Quadra's for 21 years now and they continue to be an outstanding Amplifier. I've been using Quadra's at both my Florida and Wisconsin QTH's. During this same time period I've owned several other Amplifiers, including 3 Alpha's, and the Quadra's have been the most reliable of them all.

I really enjoy the built-in 4-Antenna Switch and the HIGH and LOW power settings. I usually operate in the LOW power setting and the Amp runs amazingly cool at 700 watts output.

The separate power supply is nice as it reduces the weight of the RF deck, and can be placed under the operating desk if wanted. The interconnecting cables are 6' in length. I have never had power supply damage due to AC line fluctuations or AC surges.

In my opinion, Yaesu hit a grand slam home run when they designed the Quadra, and that's why I own 3 of them. Though I've occasionally over driven my Quadra's it's never resulted in a blown final, unlike many solid-state Amps currently being sold. Also, the Quadra fans are quieter than most solid-state Amps.

Therefore, the Quadra deserves a "5" in my opinion.

73, Dick- K9OM
W5XH Rating: 2020-07-27
Voltage dropout VP-1000 failures (X2) Time Owned: more than 12 months.
I purchased my Quadra System in 2014, and it served me well, but after two years it succumbed to the common surge suppressor resistor failure when the power mains fluctuated one day. Yaesu repaired it under warranty, and it worked well for three years until we had several voltage dropouts in a short time. This time a loud "pop" came out of the VP-1000 along with the smell of burning electronics. I took it apart, and the large Q107 transistor had completely exploded, and there were two obviously burned resistors in the same circuit. Off it went to Yaesu, but they said that it could not be repaired. This is the only piece of ham gear that I have had that destroyed itself when the mains voltage dropped our for a second or so, but this is a common failure in this amplifier. So, one day I will attempt to replace the burned components along with a few other components in the circuit that may be faulty. Otherwise I have a nice RF deck that would work fine if only it had a functioning power supply. My amplifier was powered through a buck-boost transformer which fed it 224 volts AC. So far, the SPE Expert 1.5K-FA Second Series that replaced the Quadra has functioned perfectly.
KX4WG Rating: 2020-05-28
An Excellent Linear Solid State Amplifier Time Owned: 3 to 6 months.
I finally received the Quadra System in April 20, after being in a production backlog in Japan. "Good things come to those that wait." My Yaesu FT DX 3000 is totally compatible by the use of a data cable to the Quadra System. The built in antenna tuner, tunes my GAP Challenger DX antenna within 1:0/1:2 vswr on most bands. The Quadra Amplifier changes bands automatically as well as memorizing the set vswr for that band. This amplifier is capable of 1.2k easily with a dedicated 220v line. I believe Quadra System would be a good investment, even thought of its expensive price tag.
WD9IDV Rating: 2020-05-17
19 Years and Still Working Perfectly! Time Owned: more than 12 months.
Sadly, I believe the Quadra has been discontinued and no longer in production.

Well what can I say that I have not said before. Nineteen years since original purchase and still in use almost everyday. I run mine at 1100-1250 watts on occasions with no issues. Normally its run at the 1000 watts. SSTV at 1KW no issues.

I use a Tripp Lite Isobar 4-Outlet 200-240V surge protector, and I think this helps with longevity...hopefully.

Factor original cost and amortize in 19 plus years, and thats a pretty good deal.



----------------------
Earlier 5-star review posted by WD9IDV on 2015-01-08

I am still pleased with Yaesu Quadra amplifier after almost 14 years of ownership. I have not had any issues in the last 14 years since my initial problem with one of the MOSFET MRF 150’s transistors going bad when it was first purchased new.

My only concern is with the LCD display. I wish it was brighter and had better contrast. My Yaesu FT-920 transceiver's display has nice contrast and brightness. The Quadra is definitely less bright and has less contrast compared to the Yaesu FT-920. One would think that Yaesu would have designed the Quadra display to match the FT-920’s display characteristics.

For reference, I have copied my previously published older review and included it below.

“Still going strong with no problems after seven years of operation. I use it almost everyday at 1100 - 1250 watts output. When I operated RTTY and SSTV I always ran it at a kilowatt. When brand new I did have a bad MRF-150 transistor, but Yaesu did replace it and has never shown any problems since being repaired seven years ago.

I run two radios into the amplifier. The first being my "workhorse" the Yaesu FT-920. The second radio is a Kenwood TS-570DG. I use an Ameritron ALB-702 amplifier buffer interface with the Kenwood radio. I have no problems using two radios with the Quadra. Works great and as expected if you read your manual.

Closing Comments:
I love this amplifier. It is very well built. The insides are a work of art. Solid Japanese electronic build quality. The control cables that were included could have been better though.
As to the price, I think it is reasonable. For the level of sophistication, quality, and technical expertise built into this amplifier, it will be money well spent over the course of its life.”

Robert WD9IDV
IK2CNC Rating: 2020-01-30
A real race Horse Time Owned: 3 to 6 months.
After my very nice experience with FTDX9000D, I decided to pair it with Yaesu VL-1000 Quadra. In Italy is not easy to find it due to it is no more exported in Europe. Few month ago I was lucky and find a mint condition VL-1000. Very easy to wire it to 9000 and is amazing the power capability of this amplifier! 1.2K very easily, but I use maximum 5-600 Watts in order to extend the life and due to legal regulation. I power it at 215-220V maximum trough an autotransformer because I've 235-245 V. in my town, it's to much for it.

In any case is a great machine!

Carlo IK2CNC
K4FX Rating: 2020-01-07
Great amp Time Owned: more than 12 months.
The Quadra is a wonderful amp. 1200 watts and it never complained. It would do full power on 6 meters as well. I contested with no problems. The Tuner actually works in this amp. With today’s current used prices, the Quadra is quite a value for a near legal limit amp.
N3ALN Rating: 2019-06-20
VP-1000 DEAD! Time Owned: more than 12 months.
My VP-1000 died and I sent it back to Yaesu and they said the main board was bad and a new board would cost over 2K. I feel I was left high and dry and now I have no working amp, I am pissed! :-(
K5LLZ Rating: 2019-06-13
Great amplifier. Time Owned: more than 12 months.
I have had mine for about 3 years now with no problems. Got rid of my tube amp amp for it. My buddy got a Pw1 about the same time and has had both of them back to Icom for problems. Got rid of both of them.
I use a Icom 756 Pro 3 with 60 watts drive and put out 900 to 1100 watts depending on the band and antenna I use. Antenna tuner works great. Can't say enough about it. Power supply is a little behind the times but don't drive it hard it should last a long time.