[Elecraft] 7610 / k3 ... amp comparisons

Tue Jul 24 09:58:39 EDT 2018

*/I will agree with everything said pasted below but for one thing which 
is Fan Noise I'm a rag chewer around 30 wpm QSK the fan will ratchet up 
to speed 3 after a few minutes of keying so the fan noise is very a 
subjective opinion not right not wrong just is, being fair in my 
assessment mine is built from a kit when they first came out.

By the way as an Icom owner of both the 7300 now parked unplugged and 
for sale and the 7610 the cw qsk is better in the 7610 but  the K3 is my 
choice for split frequency DX QSK exchanges over both of the Icom radios 
the 7610 is a big improvement how ever I find it clumsy to work Split 
listening up stuff .... the Internal Keyer in the K3 is much better 
there is a better range of adjustments available in the Elecraft 
internal keyer ....would I like to see it like the Supper CMOS 3 keyer 
choices heck yes ....Icom gives you little choice my fist after a lot of 
practicing and paying attention is better with the Icom but not as good 
as the Elecraft Mode A Mode B is most important choice but even more 
choices would be nice like the length of (each element) not just the 
spacing between each element.

One important discovery the 7610 muted VFO A from a S9 signal just up 
the band on vfo B while chasing the Baker Is DX-Pedition it took me a 
while to (find) out this is what was going on wanting to master the 
listening up pile up with the 7610 and only one VFO knob  takes getting 
used to the cw monitor side tone is 5 taps deep in the menu to change I 
can not hear it well enough even set at 100% you have to turn down the 
RF gain making the guy on the island weaker copy then turn up the AF 
gain making the side tone for my fist louder so I can hear what I'm 
doing on the paddle, (self defeating) and *stupid* The cw side tone is 
tied to the *flipping* AF gain not separate like in the K3..... 
*stupid*. If you can't hear the island on one VFO because a big signal 
is a couple cycles up push his button never listening to *hear the guy 
on the island* who he is working or know if he is calling Mr button 
pusher that kind of qrm is not necessary nor productive to the run rate. 
Mr button pusher was not working QSK was he waiting for a computer to 
tell him the island is calling?????
You can't fix *STUPID*..............front end muting from a big signal 
near by is a problem. Now change to head phones you ears get blown up by 
the side tone level needing 5 taps deep in the menu then adjusting it 
even one more time *stupid* at the very least this adjustment needs to 
be in the MULTI button empty spot menu ...........like it is for SSB 
don't hold your breath waiting to Icom to fix this over site.
Both radios drive the KPA500 well the hook up is straight forward easy 
to do QSK  relays perfect the best.
Oh yea Icom needs a menu setting SPK+Phones, a rear plug for 3.5 Mic 
input and 3.5 Elec-Key input.

  Back to Baker Is DX I finally gave up switched to the K3 bam in the 
log ...... You get what you pay for there is a lot to like with the 7610 
a lot, many features you don't get with the base set up in many other 
radios the price is really good but if you want to race  Pro Stock it is 
not cheep performance counts and cost....

Not sorry.. never have been on my choice I have put a helper fan on top 
to push air as soon as the amp comes on cooling it from before key down 
lower start temp. My shack is hottest room in the house the station is 
in a corner
the helper fan is a Noctua fan NF-a9x14pwm low profile. To be fair a TV 
is always going two computers big monitor all making the room hotter. I 
get a couple more minutes till the temp runs to 65c kicks speed 3 on 
which is my time out timer to turn it over,  the equipment is also 
stacked to save space I found that at full song speed 3 kicks in if I'm 
in the middle of some sentence and keep going the fan will run at speed 
3 then go back to speed 2 .....be nice to set the on set of speed 3 a 
bit higher in the tempeture range. This amp is well built really does 
the job I'm happy happy happy, and yes my Z bracket has the correct 
length hold down screws it will click when cooling down ( not always ) 
not real objectionable for me the fan noise more annoying. The screws 
were re-tightened after a heat cycle one at a time like you do with race 
engines.

I also took the advice to run the amp to its limit not at 400w out it 
does seem the final is most efficient and running a tad cooler and 
longer before speed 3 which is annoying and to be avoided in my opinion.
The helper fan starts things from a cooler lower temperature as well 
giving a bit longer run time to speed
speed 3 another thing that can be done which I did before the helper fan 
is run speed 1 at turn on keeping the idle temp lower.

The Quadra has been in stand by ever since the KPA500 made it debut 
plugged in and doing its timed maintenance mode, running the relays and 
noisy fans. I would switch between them, now its not even plugged in I 
do not see the need for what I'm doing....say that to say this I just 
might get the new 1500 if I can sell the Quadra ( new 1998) never an 
inrush current problem first run second version was the best, the only 
problem replaced the 4 meter lights a few years ago. Elecraft ATU is so 
good compared to the Quadra with  RF sniffing power needed is a speck in 
the ocean compared to the 50 watts into a perfect load Mr Quadra want's 
to see.

Regards
Art
ka9zap

/*After much investigation and consideration I elected to purchase the 
KPA-500/F.   Since I have the K3S and now the KAT-500,  I've "trained" 
the KAT-500 for the antennas and frequencies on each band.  With the VFO 
tracking, I dial the frequency and everything follows.

Specifically the KPA-500 I find to be very quiet, it delivers 500 watts 
+ on every band, 160 - 6M.  Drive power is about 25 watts on every 
band.  The fan is quiet and is of no concern even at the highest 
speed.   It does step down quickly as the amp cools. Normally the fan is 
off until the temperature rises.   Using it on FT-8 at 500 watts out, it 
will increment to #2 on occasion.    The input always appears as a 1:1 
SWR to the transceiver.    The high SWR circuit does protect the amp and 
is fast.  With my station configuration I feel as though I have a 500 
watt transceiver, automatically selecting antennas and tuning as 
needed.   I touch nothing but the VFO knob or enter the frequency for 
the next band. Everything switches silently and automatically.

I come from a line of tube amps in the 1000 to 1200 watt class. Fans run 
all the time.  Power output varies with band as well as drive 
requirements.  Most seem to be optimized for 20M.   My last tube amp was 
a AL-80B and it was one of the smoothest tuning amps I've used. Power 
out always 1000 + watts.   But it required tuning with each frequency 
and band change.

The difference in power is 3 dB or only 1/2 S unit.    All works for 
me.  I vote for the KPA-500.