7000 DLE MK3 - Overheating/Fan Concern

rdwing
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7000 DLE MK3 - Overheating/Fan Concern

Postby rdwing » Tue Aug 02, 2022 1:29 am

The brand new 7000 DLE MK3 seems to get extremely hot while operating. Does not seem to meet 100W ICAS at all. Power output drops substantially as the heat builds up. I keep the radio elevated on some extra tall feet, but it doesn't seem to help.

Does anyone know what the fan situation is on the newer radios? I checked and the built in fan is actually turning but is extremely quiet and seems to make minimal airflow. I checked the ext fan terminals in the back and there is a constant 12V available there.

Any ideas?
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby w-u-2-o » Tue Aug 02, 2022 11:49 am

What modes and what duty cycles are you running that are making the hardware "extremely hot"?

ICAS (intermittent commercial and amateur service) has no formal standard defined. Informally, back in the tube days, it was defined as 5 minutes on, at least 5 minutes off. With solid state making this 3 minutes on, at least 3 minutes off has been discussed.

A lot of people run into problems with FT8 and FT4. The reality is that even though it's a 50% duty cycle operation, 15 seconds on and 15 seconds off is tantamount to 100% duty cycle because 15 seconds is just not enough time for the heatsink, which is the extruded chassis on all ANAN models except the 8000, has no time to cool off significantly.

The cooling design of all ANAN radios except the 8000 has always put a strong emphasis on quiet operation and a desire to use a low cost, extruded chassis. The bad news is this makes for a very low performance thermal design. The good news is that the problem is insanely simple to fix. All you have to do is blow just a tiny bit of air across the top surface of the chassis, primarily on the right hand side of the top surface where the RF power transistors are screwed into the chassis.

To read more about this, see my ANAN-100D cooling project page. Nothing significant has changed in terms of the thermal design between the original ANAN-100 and the ANAN-7000, so it all still applies. You can use the rear 12V accessory port to add an external 12VDC fan. Or there now exists a wonderful selection of USB-powered cooling fans that people use for cooling routers, cable boxes and whatnot that would work perfectly for this.
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby rdwing » Tue Aug 02, 2022 6:16 pm

Thanks for the information.

I noticed this while attempting the PA gain calibration. This started becoming quite difficult to do because the power output drops substantially while transmitting. This is key down CW into a dummy load.

Following your train of thought and the generally accepted 50% duty cycle for ICAS, I have tested 60 minutes of 3 min on/3 min off cycles while measuring the forward power/voltage and case temperature. The maximum power the Mk3 can sustain is 72W(2.90V) of forward power during this test. The case reaches a temperature of 57C and ambient temperate is 24C. 7 minutes into the test and the radio is only doing 80W.

The fan does not seem to be temperature controlled in any way. It does not appear to change speed, and there is little to none warm air being expelled from any vents on the case. The only cooling seems to be conduction into the extruded chassis.

Spec: RF Output Power: 100W PEP SSB, FM, RTTY, Digital; 1-30W AM, 100W CW
Improvements: Rugged Aluminium Extruded chassis for excellent thermal dissipation and Rx/Tx isolation.
PA board improvements for higher duty cycle, 100% ICAS duty cycle supported.


When I hear the words 100% ICAS duty cycle supported, along with the RF output spec as it is, I expected to get 100W or close to it during xmit time, not 72W. I think it should be noted that meeting the 100% ICAS duty cycle means it should do rated output for the time period. And that 3 min on 3 min off is pretty conservative and wouldn't stand up to contest conditions.


Do you know where one can purchase the right connector for the external fan connector? I have tried to lookup the given part number but haven't been successful in locating it for purchase.
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby w-u-2-o » Tue Aug 02, 2022 7:22 pm

rdwing wrote:Following your train of thought and the generally accepted 50% duty cycle for ICAS, I have tested 60 minutes of 3 min on/3 min off cycles while measuring the forward power/voltage and case temperature. The maximum power the Mk3 can sustain is 72W(2.90V) of forward power during this test. The case reaches a temperature of 57C and ambient temperate is 24C. 7 minutes into the test and the radio is only doing 80W.

What band(s) did you do this on? The 6M band that you are having trouble with, or some other band(s)? What behavior do you get when you exceed 72W of power during this test?

The fan does not seem to be temperature controlled in any way. It does not appear to change speed, and there is little to none warm air being expelled from any vents on the case. The only cooling seems to be conduction into the extruded chassis.

That is correct on all counts. The fan does very little to cool the main RF power transistors. It's really only effective at moving enough air to cool the FPGA and other parts on the Orion board.

At one time the design did include a fan controller, but the implementation of that circuit was "sub-optimal" and it was abandoned in later versions of the 7000DLE. I don't know why they simply didn't fix the design in later versions. You can read more about that here: viewtopic.php?f=17&t=2682&p=13874

Then there were a batch of MKII units that came out with no external fan power connector. You can read about that here: viewtopic.php?f=17&t=3914&p=19403

When I hear the words 100% ICAS duty cycle supported, along with the RF output spec as it is, I expected to get 100W or close to it during xmit time, not 72W.

W4NNG did a similar test and reported similar results (80W max.): viewtopic.php?f=17&t=3622&p=12976

I appreciate your concerns, as no doubt do many others. When my 100D was my daily driver I had the external fan as described by my article linked above. It was either that or sell the ANAN. When I got my first amplifier it ceased to be a problem. Now I have an 8000 as my daily driver (100D backup) and an even bigger amp so it's even less of an issue. It's not been a huge issue for most people because most people paying this much for a radio have already invested in an amplifier. But for anyone running barefoot it can be a real problem without an external fan.

I agree with you that when you pay this much for some hardware you expect it to be better than perfect. Unfortunately in many ways it is not. The 7000 series is certainly much better than what came before it, but it still has its weak spots. And remember you didn't pay anything for the firmware or the software. There is some risk living at on the bleeding edge of HF SDR technology, unfortunately, and some trade-offs as well. And if you question Apache about it there will be some discussion as to what duty cycles are really associated with ICAS, and since there is no formal standard there might be some disagreement there.

Do you know where one can purchase the right connector for the external fan connector? I have tried to lookup the given part number but haven't been successful in locating it for purchase.

If you searched this forum for "fan connector" you would have found this post very quickly: viewtopic.php?f=17&t=2646&p=4349
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby rdwing » Tue Aug 02, 2022 8:32 pm

w-u-2-o wrote:What band(s) did you do this on? The 6M band that you are having trouble with, or some other band(s)? What behavior do you get when you exceed 72W of power during this test?

Of course not. Center of 40m into a dummy load. This is with 100W drive, the power sags to 72W probably due to temperature. Can you clarify what you mean by exceed 72w? Adjust the PA gain? It's set for 100W during normal operation.
w-u-2-o wrote:At one time the design did include a fan controller, but the implementation of that circuit was "sub-optimal" and it was abandoned in later versions of the 7000DLE.

Fine, they need to fix the website then. The product specifications still indicate a temperature controlled fan. They are advertising features not delivered. Seems like its been at least 2/3 years since that change was made. Why isn't it updated? There were able to update it with new or changed selling points, so no excuses.
Screenshot 2022-08-02 123014.png
Specs from website
Screenshot 2022-08-02 123014.png (38.69 KiB) Viewed 5242 times

w-u-2-o wrote:W4NNG did a similar test and reported similar results (80W max.): viewtopic.php?f=17&t=3622&p=12976

I appreciate your concerns, as no doubt do many others. When my 100D was my daily driver I had the external fan as described by my article linked above. It was either that or sell the ANAN. When I got my first amplifier it ceased to be a problem. Now I have an 8000 as my daily driver (100D backup) and an even bigger amp so it's even less of an issue. It's not been a huge issue for most people because most people paying this much for a radio have already invested in an amplifier. But for anyone running barefoot it can be a real problem without an external fan.

I agree with you that when you pay this much for some hardware you expect it to be better than perfect. Unfortunately in many ways it is not. The 7000 series is certainly much better than what came before it, but it still has its weak spots. And remember you didn't pay anything for the firmware or the software. There is some risk living at on the bleeding edge of HF SDR technology, unfortunately, and some trade-offs as well. And if you question Apache about it there will be some discussion as to what duty cycles are really associated with ICAS, and since there is no formal standard there might be some disagreement there.

We definitely agree on some things there, but I don't really agree that this is the bleeding edge of HF hardware anymore. In fact I'd wager that this project has been falling behind for quite some time. The design of the core is essentially unchanged for the last 10 years except for small things here and there. It is a testament to the soundness of the original design, and exceptional volunteer team that it has remained a viable product for this long. In 2012 this was so far ahead of everything else, however in 2022 there are some glaring omissions and real competition in the marketplace.

I don't want it to be better than perfect, I just want it to do what it says on the tin. That's how commerce works. A lot of consumers let companies get away with a lot, but if I purchase something I expect that it performs to spec. Especially for this kind of money. The Anan is not cheap.

As a new consumer of this particular product, I have been disappointed now a few times by misleading or inaccurate specifications and marketing literature.

Expectation: 1.15Mhz wide or greater Panafall, at least 3 "front ends".
Reality: 192 khz max.

Expectation: 7 receivers available to use and park wherever I want on HF.
Reality: 1 waterfall, 1 receiver. 2nd MultiRX receiver sometimes works but must be within 1st receivers IF and is buggy. Only 3 are actually available and unused in hardware, all others already used (RX1/RX2/PSrx/PStx). RX2 not very useful because cannot switch to transmit wherever RX2 is if already using MultiRX.

Expectation: 2 ADC's, fully configurable with ability to assign antennas as desired.
Reality: ADC1 has 3 switchable ports. ADC2 has a single fixed port only.

Expectation: Wideband view of entire ADC range, 0-62 Mhz.
Reality: Completely broken

Expectation: Voltage, current, chassis temp monitoring per brochure.
Reality: Voltage only

Expectation: Gigabit ethernet and Protocol 2
Reality: 100 Mbit only and Protocol 1

Expectation: Software control of all relays in the radio, including PTT.
Reality: PTT-out is fixed, you cannot disable PTT-Out. Only can disable PTT-In.

Expectation: 100w 160-6m, key down at least for some reasonable time period.
Reality: Not 100w on all bands, and not able to sustain 100w key down for more 60 seconds. By 2 minutes it's already down 10%. Now, the 6m problem may be a defect, but this inability to sustain 100w is true on all bands. And a defective LPF shouldn't make it out of QC.

w-u-2-o wrote:If you searched this forum for "fan connector" you would have found this post very quickly: viewtopic.php?f=17&t=2646&p=4349

Thanks for the link. I searched for the part number as indicated in the manual (TE#158619-2) and couldn't find it. Hopefully this post will serve any future customers that come looking for the right connector.
Screenshot 2022-08-02 122534.png
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Screenshot 2022-08-02 122534.png (242.42 KiB) Viewed 5242 times
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby Tony EI7BMB » Tue Aug 02, 2022 9:23 pm

Thanks for the digram . Think I might try an external fan although there are posts for second internal fan on my 7000 mk2 . I replaced the original fan with a quieter unit with temp sensor so might use that type again for a second internal fan.
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby w-u-2-o » Tue Aug 02, 2022 10:52 pm

rdwing wrote:Of course not. Center of 40m into a dummy load. This is with 100W drive, the power sags to 72W probably due to temperature. Can you clarify what you mean by exceed 72w? Adjust the PA gain? It's set for 100W during normal operation.

Ignore my last transmission ;) I did not understand that power was sagging to 72W from a nominal 100W.

Fine, they need to fix the website then. The product specifications still indicate a temperature controlled fan. They are advertising features not delivered. Seems like its been at least 2/3 years since that change was made. Why isn't it updated? There were able to update it with new or changed selling points, so no excuses.

The current web page:

https://apache-labs.com/al-products/105 ... ition.html

Is much improved upon those from years past, and much of your commentary seems aimed at some of the past versions of the website, which were, to put it as politely as I can, somewhat deceiving. For example, are there 7 DDCs available for assignment in the firmware? Yes, but the most commonly available software did not make use of them in a freely independent way, so should it really be advertised in that manner? Indeed, since Apache only builds and sells hardware, should they be mentioning functionality that is wholly dependent on the firmware and software at all?

When I bought that first 100D (used, from someone who was upgrading to the 200D), I was just as taken in by what was on the website, and my reaction was pretty much as visceral as yours probably is. Eventually I rolled over on the whole issue because the combination of hardware, firmware and software did things no other radio did, and that remains true to this day. I submit this therefore still constitutes the state of the art in terms of functionality available to hams, with the exception of remote op's, where the state of the art resides with Flex. A few other rigs have mildly better electrical spec's on the Sherwood list, but the differences are not noticeable unless you have serious co-site issues (contesting stations, nearby ham neighbors, etc.)

So philosophically you have to decide if the liberties taken with both design execution and the advertising are sufficiently off-putting to give up the unique capabilities of the radio (remembering that radio = hardware + firmware + software, not just hardware). Many people have decided in both directions.

Now getting well off topic (throwing myself under my favorite pet peeve bus for this), but in my mind the lack of Protocol 2 is the real showstopper. And this is in no way meant to put any pressure on Rick. Apache made their decision to release hardware without any planning for P2 support. Apache's emergency (if there is one) is not Rick's emergency, nor should it be.
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby rdwing » Wed Aug 17, 2022 11:04 pm

Now that P2 is out for this model, can we continue this discussion?
I believe that at some point there was temperature controlled bias for the 7000. Is this still true for the Mk3?
What is the proper way to calibrate the PA gain? At which temperature level??

Just to reiterate, if I calibrate for 100w on a cold radio, by the time its warmed up, if I key down the power will sag quite as bit.


Re: my comments about the website, that data was taken from the current page for the 7000 DLE MkII, and the PDF brochure linked on that page. I think those are fair game, and a consumer has the right to be upset about some BS marketing. If it's no longer current, Apache needs to change it. That was something I pointed out...
Anyways I still believe my comment about the entire Apache line no longer representing SoTA is correct...the future lies with thin SDR's. I see some discussion from 8 years ago now when there was a slightly misguided thought of building a Jetson powered single-board computer to run the radios internally. Disappointed still that it never came to fruition. The whole world is much more internet connected and networking driven than it was a decade ago, and the lack of integrated processing in the radios is a glaring hole in the product lineup, imho. x86 is dying.
Even moreso with Protocol 2, the data rates required on the endpoint are crazy. It is unlikely to stay competitive in the market long term, and I hope for Apache Labs' sake they choose to invest in a newer architecture in the future, for all our benefit.
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby w-u-2-o » Thu Aug 18, 2022 1:09 pm

rdwing wrote:Now that P2 is out for this model, can we continue this discussion?

P2 will have no bearing on this problem. It's a hardware issue.

I believe that at some point there was temperature controlled bias for the 7000. Is this still true for the Mk3?

There is no direct control over PA bias by any of the SDR cards designs from the original Hermes all the way through the current Orion MKIII. All bias control circuitry is located on the PA board, and there is no software control of that circuitry.

The PA boards in the older 7000 designs are essentially the same as on the newer designs. There are minor variations in fan control and current measurement; the RF sections remain identical.

Looking at the schematic, while there is a temperature-compensated bias voltage reference, that compensation is only to maintain a constant voltage output, not one that varies with RF power transistor temperature. So it appears that the answer is that none of the designs incorporate temperature compensated bias.

What is the proper way to calibrate the PA gain? At which temperature level??

There is no proper way. It's whatever way works best for your particular situation.

For instance, I run exclusively with an amplifier. I calibrate for maximum accuracy at the nominal full-power drive level (approx. 40W) that I use with my amp.

[url]Just to reiterate, if I calibrate for 100w on a cold radio, by the time its warmed up, if I key down the power will sag quite as bit.[/url]
Because I don't run the radio at full power I can't tell if you have bad hardware or if this is just a natural consequence of the design. Perhaps someone else might chime in with more comparable results.

Re: my comments about the website...

Probably better to start a separate topic on that subject.
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby N7CXI » Fri Nov 11, 2022 11:34 pm

Continuing a stale thread…

Has anyone gone to the effort of working up a bias compensation mod for the 7000 DLE MKII PA ?

When using a high-gain LDMOS amp, the difference between cold and warm drive settings can can cause a variation of over twenty percent in the amp output. That’s too much.

The 7000 DLE MKII is my go-to rig most of the time, but bias temperature drift and UDP packet uncertainty (for two) continue to annoy me. Oh and the switch-mode regulator noise…

Seems like we got 80% of the way there and then went on cruise control design-wise. Adding a 500-watt LDMOS PA option is cool, but pardon me if I sit this one out until I see someone take a hard look at the hardware. If we see legacy design issues, I’ll skip it and use what I have until something truly better comes along.

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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby w-u-2-o » Sat Nov 12, 2022 2:10 pm

N7CXI wrote:Seems like we got 80% of the way there and then went on cruise control design-wise.

A truer statement was never written.

Historically speaking, this is exactly what one would expect, for a variety of reasons.

First, it is important to remember that the basis of the present day designs remains the open source work that was done under the openHPSDR banner. This includes all of the hardware, which in present day form exists as derivative works under the original open source license. Given that this all started as a hobby-time activity, people did it because they wanted to do it, not because they were getting paid to do it. Combined with the fact that the design team was very, very small, it is not at all unexpected that when the design reached a level of usability considered acceptable to the, by then tired, design team, they were happy to take a break and enjoy the fruits of their labors. And the cherry on top was that the design was so far ahead of everything else (with the possible exception of Flex), any minor shortcomings were eclipsed by its overall performance. Today this might not be as true. With direct sampling HF hardware now available from Icom, Yaesu, Flex, and Expert (can Kenwood be far behind?) such performance is becoming commonplace. Although IMHO software functionality still remains the most powerful and important discriminator.

But we are discussing hardware here. If you have received schematics from Apache, you can refer back to the original openHPSDR website, http://openhpsdr.org/index.php and see just how closely the latest Apache products follow the original designs, in particular Hermes, but more to your point the Alex filter board and the Apollo and Munin amp designs. Again, this is no surprise because, AFAIK, some of the original design team continue to work as major contributors to Apache hardware design. Thus, today, without either the open source community or Apache bringing in new design knowledge or resources, it is unlikely there will be anything but incremental design improvements in the foreseeable future.

It's worth noting that from an SDR perspective, a number of folks from the openHPSDR community, with Apache support, came close to realizing a very major improvement in the architecture, albeit not at the analog RF end. This project was called Minerva. You can see a video here: https://www.youtube.com/watch?v=HOfTSq2O7mU

Minerva would have solved a LOT of problems in the networking, development and processing areas. By moving the raw ADC and DAC datastreams to PCIE, this allowed all FPGA functionality to be moved into the GPU processing space, essentially eliminating the need for VHDL or Verilog expertise in the community, removing the impediments of the Quartus Lite development environment, and lowering the cost of the hardware. It would most likely have also spurred development of a thin client/server architecture.

Sadly, even though the group did come up with a viable hardware design, prototypes of which were produced by Apache, and some very viable prototype software, the effort died, apparently due to some folks walking away from the effort. Without the support of these open source, volunteer developers, Apache could not continue with the design on their own. Nevertheless it remains as an example of how the past and present design environments function (or don't function) for Apache and the openHPSDR community.

Adding a 500-watt LDMOS PA option is cool, but pardon me if I sit this one out until I see someone take a hard look at the hardware. If we see legacy design issues, I’ll skip it and use what I have until something truly better comes along.
Assuming all of the players remain the same as in the past, it's unlikely the RF design of the new hardware will look much different than what exists today. Nevertheless, sometimes "better is the enemy of good enough" needs to be considered. At the price point proposed, the hardware costs little more in 500W form than it does in 100W form. For many, getting to 500W for only an additional $800 might be worth a few design shortcomings.
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby N7CXI » Sun Nov 13, 2022 5:59 am

At the price point proposed, the hardware costs little more in 500W form than it does in 100W form. For many, getting to 500W for only an additional $800 might be worth a few design shortcomings.


An excellent point. Based on that alone, the new hardware will present gains to many, (but based on my assumptions) just not to me.
I have two LDMOS amps, one my design and one commercial. Power is easy. Spur-free completely stable operation not so much.

After I wrote the earlier message, I reflected a bit on the current state of affairs on HF. Yaesu, for example has very capable RF hardware, but in my opinion falls short in presentation. (user interface) The resale rate of FTDX-101xx rigs would seem to support that statement. ICOM, again in my opinion only, does a better job with presentation, but limits things like bandwidth to someone's very conservative view of what amateur radio "should be" - and that makes the 7610 much less interesting to me. Flex services their market, which doesn't appear to include experimental or high-performance DSP, and their apparent mission is to keep everything inside the FPGA and the clients thin enough for good network performance. Kenwood? I have no idea at all what motivates them. If Expert's software was open and the hardware was better reviewed I might consider spending 2300 USD on a dice-roll. As things are, probably not.

So here I am. I have a number of HF rigs, but the big, ugly silver box with the obligatory PC remains my most-used radio. I should probably stop complaining and use it. :D

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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby w-u-2-o » Sun Nov 13, 2022 12:52 pm

Horses for courses. Every direct sampling HF transceiver on the market has something to offer. If only we could get all the best features in a single radio. We can't, so we have to choose, and choices involve trade-offs. But discussions like this are good, because there always needs to be some pressure to improve the breed.
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby W3MMR » Wed Feb 08, 2023 12:56 pm

I figured I'd add my experiences to this old post.

I've been having a power loss issue with my 7000dle (mk1 blue face) as well. I operate mainly AM, running 10w +/- 1w into an amplifier. After the radio warms up, I experience the power loss as well. 1 watt less off carrier and 5w or ao PEP. That much loss from the radio ends up being 25w less of carrier on the amplifier and sometimes 100w of peak power. So last night I decided to put a fan on the right rear (looking at it from the front) of the radio. Doing 3 minutes on, 3 minutes off, of 50w carrier, I would lose 1 watt of power. By the time I would key back up after 3 minutes, the fan would cool things down and the power would be back at 50w. I haven't tried 100w to see what the power loss would be.

If it keeps becoming an issue. Even with two fans, I may contemplate breaking the radio down, putting the final board on a heatsink, mounting in a rack cabinet, pressurize the cabinet, and exhaust the air across the heatsink. I know someone who has done this and it works well.


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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby n2gq » Wed Feb 08, 2023 1:25 pm

Hi,
Have you checked the power pole connection? Are they getting hot?
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby w-u-2-o » Wed Feb 08, 2023 2:20 pm

W3MMR wrote:I figured I'd add my experiences to this old post.

I see you've updated this topic instead of your original.

So last night I decided to put a fan on the right rear (looking at it from the front) of the radio. Doing 3 minutes on, 3 minutes off, of 50w carrier, I would lose 1 watt of power. By the time I would key back up after 3 minutes, the fan would cool things down and the power would be back at 50w.

The difference between 50W and 49W is less than 0.1dB. That's as perfect as you are going to get with any radio.

Assuming a U.S. legal linear amp with 15dB of gain, that corresponds to 1581W and 1550W.

You are not going to do better than that with any amateur radio equipment. So it would seem that cooling the case works pretty well. Would you agree?

If it keeps becoming an issue. Even with two fans, I may contemplate breaking the radio down, putting the final board on a heatsink, mounting in a rack cabinet, pressurize the cabinet, and exhaust the air across the heatsink. I know someone who has done this and it works well.

Unless you are getting into the AM broadcast business (and there are a number of hams who would qualify ;) ) going to such lengths would seem unnecessary.
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby W3MMR » Wed Feb 08, 2023 5:16 pm

w-u-2-o wrote:
W3MMR wrote:I figured I'd add my experiences to this old post.

I see you've updated this topic instead of your original.

So last night I decided to put a fan on the right rear (looking at it from the front) of the radio. Doing 3 minutes on, 3 minutes off, of 50w carrier, I would lose 1 watt of power. By the time I would key back up after 3 minutes, the fan would cool things down and the power would be back at 50w.

The difference between 50W and 49W is less than 0.1dB. That's as perfect as you are going to get with any radio.

Assuming a U.S. legal linear amp with 15dB of gain, that corresponds to 1581W and 1550W.

You are not going to do better than that with any amateur radio equipment. So it would seem that cooling the case works pretty well. Would you agree?

If it keeps becoming an issue. Even with two fans, I may contemplate breaking the radio down, putting the final board on a heatsink, mounting in a rack cabinet, pressurize the cabinet, and exhaust the air across the heatsink. I know someone who has done this and it works well.

Unless you are getting into the AM broadcast business (and there are a number of hams who would qualify ;) ) going to such lengths would seem unnecessary.



I hadn't gotten around to updating the other post. I was very intrigued after reading this and figured I'd add my experiences to maybe shed some light on the pros of adding an external fan to the case. I'll put it to a real test this weekend when I have some extended time to operate instead of just 30 minutes in the morning before work. I also would like to test at 100w just to see how it performs. But the external fan has really seemed to help cool things down completely between transmissions, so yes, I would agree.

As far as building another cabinet, I agree on it being unnecessary. I suppose I was just thinking out loud. I'm sure you've seen AC2IQ's modifications. Something like that. If not, theyre on his QRZ page. But it would be a lot of work. And more so i would do it just to do it.
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w-u-2-o
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby w-u-2-o » Wed Feb 08, 2023 5:20 pm

Definitely post back with how it finally works out, please!
N7CXI
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Re: 7000 DLE MK3 - Overheating/Fan Concern

Postby N7CXI » Wed Feb 08, 2023 6:38 pm

Seems it could be a good time to review whether an add-on bias compensation circuit for the brick should be considered.

I have the ginormous silver-case 7000 with no internal PC, so the space constraints are different than with the blue and black cases.

Unfortunately, I have far more projects competing for time than I’ll actually get done, and this one isn’t at the top of my wife’s list.

73,
Jim N7CXI

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