7000 MK2 & Temperature controlled fan

m1tzr
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7000 MK2 & Temperature controlled fan

Postby m1tzr » Thu Dec 03, 2020 9:59 pm

I have recently acquired a black 7000mk 2 and find the fan very loud compared to my old 100d.
I have seen in the info that the 7000 has a "temperature controlled fan, internal and optional external"
These lead me to believe the internal would come on and off as needed or increase in speed as need?
Mine is just running full speed ahead from switch on.
Is this normal or is there a setting in Thetis I need to change?
Looked everywhere and can't find anything.

Tnx
Paul
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w-u-2-o
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Re: 7000 MK2 & Temperature controlled fan

Postby w-u-2-o » Fri Dec 04, 2020 2:11 pm

I've lost track of exactly what's what with 7000 MKII fans. The original MKII's, the ones that optionally had an internal PC, used a fan controller chip. Unfortunately the implementation used a FET instead of the recommended BJT and the very sharp rise/fall times on the PWM waveform made the fan extra noisy. This problem, and the circuitry, is detailed in this topic:

viewtopic.php?f=17&t=2682&p=8466

I seem to remember that later variants of the MKII have their fans wired to be on all the time, but I'm not 100% certain.
m1tzr
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Re: 7000 MK2 & Temperature controlled fan

Postby m1tzr » Fri Dec 04, 2020 2:36 pm

"I seem to remember that later variants of the MKII have their fans wired to be on all the time, but I'm not 100% certain."

Would make sense and explain why I can't find anything to slow it down.

Cheers for the response.

Paul
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pa1hr
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Re: 7000 MK2 & Temperature controlled fan

Postby pa1hr » Fri Dec 04, 2020 2:47 pm

GD!
Since about half a year I use the same black 7000MkII and can confirm that the internal fan is 'always on'. I consider to replace it by a Noctua, which is more silent. https://noctua.at/en/products/fan
73, Hans.
--

73,
Hans Remeeus (PA0Q/OE3JRC)
https://pa0q.nl
"Communication is about people, the rest is technology"
m1tzr
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Re: 7000 MK2 & Temperature controlled fan

Postby m1tzr » Sat Dec 05, 2020 7:47 pm

Thanks Hans

It is an option I will consider. I have used Noctua fans in other radios to quite them down with great success.

Paul
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W4NNG
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Re: 7000 MK2 & Temperature controlled fan

Postby W4NNG » Sat Dec 19, 2020 5:20 am

w-u-2-o wrote: ...
I seem to remember that later variants of the MKII have their fans wired to be on all the time, but I'm not 100% certain.


Mine is always on. Kind of means these versions don't meet the 'temperature controlled fan' spec. My black 7K runs the fan at the same speed coming on cold as it does when it's overheating. FWIW my unit does not appear to meet the 100wt ICAS. My best estimate is 80wts ICAS
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w-u-2-o
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Re: 7000 MK2 & Temperature controlled fan

Postby w-u-2-o » Sat Dec 19, 2020 2:01 pm

W4NNG wrote:FWIW my unit does not appear to meet the 100wt ICAS. My best estimate is 80wts ICAS
I'm not familiar with the construction of the 7000 series. However, if it is anything like the construction of the 100 and 200 series, where the final RF power transistors are mounted to the chassis and use it as a heat sink, it is fairly trivial to improve your cooling substantially by adding just a small external fan. See this link:

http://wu2o.dyndns.org/wu2o_fans.html

With an external fan on 100 or 200 series hardware you can obtain 100W at very high duty cycles.
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W4NNG
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Re: 7000 MK2 & Temperature controlled fan

Postby W4NNG » Mon Dec 21, 2020 5:02 pm

w-u-2-o wrote:
W4NNG wrote:With an external fan on 100 or 200 series hardware you can obtain 100W at very high duty cycles.


Understand -- Besides duty cyc problem, I'd prefer not hearing the fan always running at max blast. I'll test the external fan port on the 7000 to see if it's on when rig is cold. If so, a 2nd fan will add to the noise while rig idling cold in receive
K1LSB
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Re: 7000 MK2 & Temperature controlled fan

Postby K1LSB » Mon Dec 21, 2020 7:51 pm

With these radios there's no need to park them on the bench. I've got my black 7K located in a corner of the shack behind a 1/2" drywall partition. I can't hear the fan at all.

Just something to consider.

Mark
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w-u-2-o
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Re: 7000 MK2 & Temperature controlled fan

Postby w-u-2-o » Mon Dec 21, 2020 8:53 pm

W4NNG wrote:
w-u-2-o wrote:
W4NNG wrote:With an external fan on 100 or 200 series hardware you can obtain 100W at very high duty cycles.


Understand -- Besides duty cyc problem, I'd prefer not hearing the fan always running at max blast. I'll test the external fan port on the 7000 to see if it's on when rig is cold. If so, a 2nd fan will add to the noise while rig idling cold in receive
That port is paralleled with the internal fan, so it will always be running. It does not take hardly any air flow to significantly improve passive convection of the chassis. You can use a very quiet fan.
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W4NNG
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Re: 7000 MK2 & Temperature controlled fan

Postby W4NNG » Tue Dec 22, 2020 3:58 am

w-u-2-o wrote:
W4NNG wrote:
w-u-2-o wrote:


Understand -- Besides duty cyc problem, I'd prefer not hearing the fan always running at max blast. I'll test the external fan port on the 7000 to see if it's on when rig is cold. If so, a 2nd fan will add to the noise while rig idling cold in receive
That port is paralleled with the internal fan, so it will always be running. It does not take hardly any air flow to significantly improve passive convection of the chassis. You can use a very quiet fan.


Using the info at the link you sent, I'm doing a little test using a pair of recovered CPU radiators with heat sink compound over the hot spot near the top side of the rig. Be nice if they drew off enough heat without a fan. Must have about 3 dozens fans . If the radiator fins don't do the job I use your quiet fan recommend.

Tnx 4 help
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KA5KKT
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Re: 7000 MK2 & Temperature controlled fan

Postby KA5KKT » Fri Apr 30, 2021 11:08 pm

Does the air flow IN via the fan opening on the bottom of the unit and OUT through the vent holes on the back panel?

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