First time Kiwi owner here. Read through the thread and came to conclusion most of the stuff is over my head. However I did do some other researcher and found this https://www.dxengineering.com/parts/dxe-rg5000hd
Depends. Will you have a transmitter in the same area? If so, something to switch the Kiwi antenna out/to ground while transmitting is ideal. If it's on the same coax/antenna, you REALLY should switch out the kiwi. But if not feasible or easy, you can look at how much signal your Kiwi is receiving when transmitting nearby, and figure out the math from there.
While the 5000 limited the signal more, it's no longer available. The HD is available, and limits things to about 13 dbm, generally. As you can see from the chart posted above, the Kiwi can handle more than 13dbm until below 5mhz. So the 5000HD will do the job most of the time.
I use a 5000HD right now, and will have an MFJ1708B-SDR inline when I have my transmitter hooked up, as they will share antennas. Then the MFJ will switch the kiwi out when transmitting, and then the RG5000HD is there as a backup/just in case something goes wrong. And my Kiwi will sit between the transmitter and amplifier, so worst case in a failure, it's going to see maybe 3-4 watts, which the 5000 HD should have no problem handling.
Tell us more about your situation/setup, and we can more accurately answer if the RG5000HD is enough for you.
So, I think I did bad. I left my kiwi 2 plugged on a long wire antenna and yammered on at 3.7 mhz. Oops. So I set the loop test to as close to the troubleshooting parameters as I could.. CW, 10mhz, matched the WF ceil/floor values and the 0.2 gain. Received signal was -80dbm, test showed -48.change. The pattern was the same though, if weaker. When the kiwi is just on and on a confirmed good antenna the waterfall's dark.
http://www.kiwisdr.com/ks/troubleshooting.pdf point 4 at the bottom indicates a signal problem from the sma to the adc input but not what could/should be done. How bad is this thing f'd in the a by me being careless?
From JKS on 5 Aug, "We're finding the Kiwi-2 electronic attenuator goes open-circuit in a lot of cases. Despite all of the protection we built in to Kiwi-2 and the external measures people take." How can I determine if that's the case here? I'm a carpenter so try to use little words haha
From your description it certainly sounds like an open attenuator. Especially if you're getting the self-test patterns, just attenuated by 40 dB.
Please send an email to sales@kiwisdr.nz (note ".nz") requesting a repair. We're having to figure out some sort of formal solution to this problem since a significant number of people are asking.
I have enough antennas that there would ne no need to use the same antenna for the transceiver and Kiwi. However they are in close proximity to each other. The Kiwi is currently on a DX LBPlus inverted "V: dipole. I have a 80meter Delta loop, a Gap Titan DX vertical and a 80M EFHW (not in image).
You guys shouldn't think using "limiters" and other such devices will save your Kiwi when any nearby transmitter is involved.
In the good old days there was always a TR switch (transmit/receive) involved that disconnected and grounded the receiver antenna input before any TX energy was emitted. Or at least a manual switch that did the same thing. Anything else is just asking for trouble.
Common sense seems to have gone out the window here..
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Common sense seems to have gone out the window here..
hey i admitted to being a careless dummy. if the jumper repair works i might just go ahead and move my kiwi 120 km down the road to my parent's acreage where i probably can't make the same bone-headed mistake that far away
This is the worst thing I have ever seen (related to Kiwi front-end damage).
Customer sends Kiwi back. Says it was installed at a remote location with other SDRs and no co-located transmitters. Died after a few weeks.
I open it up, start some measurements and see that three of the four 30 MHz LPF inductors are wrong. They're black instead of the blue ones from Murata we've specified in our bill-of-materials. So I immediately think the factory has substituted some cheap-ass parts. Then I measure an open circuit on one of them so I go very gently poking at it. And the black part in the center flakes off, exposing the windings underneath. And then it dawns on me what's happened: Those three inductors are burned up.
In the photo below (cellphone taken through a microscope) the burned inductors originally all looked like the one on the left. The two on the right have had the windings exposed. The right inductor had broken wire in the winding.
How can this possibly have happened? Everything else is intact (see schematic: kiwisdr.com/docs/KiwiSDR/kiwi-2.schematic.pdf) The two 100V series coupling caps ahead of the LPF are fine (not shorted, correct value). The TVS and GDT are fine (not shorted). The 100k ohm static bleed resistor is fine. Even the small value caps on the LPF are fine.
Was there a pulse of energy on the antenna so severe it caused the 3 of the 4 inductors to burn up like that? Like fuses? If it were a DC short somehow the 4th inductor should have showed similar damage I would think. Like if the attenuator failed and put 3.3V on its input. But there's no ground path anywhere. The LPF caps are 50V. The series caps are 100V.
We did have one person recently say a number of components failed on their Kiwi. Including the first LPF inductor (L401) and the ADC preamp. But the photo included only showed it post-repair (L401 pads bridged over). The other inductors looked fine.
Wow. I doubt a pulse. Not enough energy to do this and not a lot of other damage as well. Maybe high power RF directly injected though. High as on the order of watts not milliwatts and for long enough to cause the heating/burning you see. Almost any likely antenna-antenna pathloss likely more than 20 dB so I doubt over-the-air causation. Since the C's survive it doesn't seem to have been related to any DC component.
Maybe a chain of events, can't see the schematic since you provided the top of the hierarchy not the front end. Presuming LPF is in front of attenuator maybe L404 went first, why that could be the case possibly inferrable from a frequency of the destroyer conjecture, then followed by L401/402 , why not L403, can't say but schematic might give a clue.
multi-page pdf, what will they think of next😀 How does one generate that, I've clearly been in KiCad too long and am out of touch with other tools!
But the fact that of series L's, one burns up while the other survives it gets really interesting thinking of a scenario that explains it. It may be that high power VHF/UHF and the SRF of the parts might have to be involved. Without looking at so-called 'parasitic' attributes it gets hard to explain doesn't it?
I like the fact you don't skimp on quality components, and won't use "compatible" ones based on cost. I used to sell electronic components in Auckland in the 80's, and it was a tough job convincing people to use quality Japanese components over cheaper (back then) Taiwanese parts - along with the very small manufacturing base in NZ and lots of suppliers.
Comments
First time Kiwi owner here. Read through the thread and came to conclusion most of the stuff is over my head. However I did do some other researcher and found this https://www.dxengineering.com/parts/dxe-rg5000hd
Would this limit enough RF to protect my Kiwi?
Depends. Will you have a transmitter in the same area? If so, something to switch the Kiwi antenna out/to ground while transmitting is ideal. If it's on the same coax/antenna, you REALLY should switch out the kiwi. But if not feasible or easy, you can look at how much signal your Kiwi is receiving when transmitting nearby, and figure out the math from there.
QST reviewed the RG5000s in 2015: https://static.dxengineering.com/global/images/technicalarticles/dxe-rg-5000_sn.pdf
While the 5000 limited the signal more, it's no longer available. The HD is available, and limits things to about 13 dbm, generally. As you can see from the chart posted above, the Kiwi can handle more than 13dbm until below 5mhz. So the 5000HD will do the job most of the time.
I use a 5000HD right now, and will have an MFJ1708B-SDR inline when I have my transmitter hooked up, as they will share antennas. Then the MFJ will switch the kiwi out when transmitting, and then the RG5000HD is there as a backup/just in case something goes wrong. And my Kiwi will sit between the transmitter and amplifier, so worst case in a failure, it's going to see maybe 3-4 watts, which the 5000 HD should have no problem handling.
Tell us more about your situation/setup, and we can more accurately answer if the RG5000HD is enough for you.
-Nate
N8BTR
http://21040.proxy.kiwisdr.com:8073/
Loots like a re-spin of their previous model, but with lots more diodes.
I don't know why they have taken this route, maybe to increase the power handling, who knows ?
Either way, it's a big markup on the <$10 cost of parts.
Regards,
Martin
So, I think I did bad. I left my kiwi 2 plugged on a long wire antenna and yammered on at 3.7 mhz. Oops. So I set the loop test to as close to the troubleshooting parameters as I could.. CW, 10mhz, matched the WF ceil/floor values and the 0.2 gain. Received signal was -80dbm, test showed -48.change. The pattern was the same though, if weaker. When the kiwi is just on and on a confirmed good antenna the waterfall's dark.
http://www.kiwisdr.com/ks/troubleshooting.pdf point 4 at the bottom indicates a signal problem from the sma to the adc input but not what could/should be done. How bad is this thing f'd in the a by me being careless?
From JKS on 5 Aug, "We're finding the Kiwi-2 electronic attenuator goes open-circuit in a lot of cases. Despite all of the protection we built in to Kiwi-2 and the external measures people take." How can I determine if that's the case here? I'm a carpenter so try to use little words haha
From your description it certainly sounds like an open attenuator. Especially if you're getting the self-test patterns, just attenuated by 40 dB.
Please send an email to sales@kiwisdr.nz (note ".nz") requesting a repair. We're having to figure out some sort of formal solution to this problem since a significant number of people are asking.
I have enough antennas that there would ne no need to use the same antenna for the transceiver and Kiwi. However they are in close proximity to each other. The Kiwi is currently on a DX LBPlus inverted "V: dipole. I have a 80meter Delta loop, a Gap Titan DX vertical and a 80M EFHW (not in image).
Thanks to all, an email has been sent.
You guys shouldn't think using "limiters" and other such devices will save your Kiwi when any nearby transmitter is involved.
In the good old days there was always a TR switch (transmit/receive) involved that disconnected and grounded the receiver antenna input before any TX energy was emitted. Or at least a manual switch that did the same thing. Anything else is just asking for trouble.
Common sense seems to have gone out the window here..
Please protect your KiwiSDR 2 from the high-level RF fields of nearby transmitters - Page 2
https://forum.kiwisdr.com/index.php?p=/discussion/comment/19545#Comment_19545done and done.
Common sense seems to have gone out the window here..
hey i admitted to being a careless dummy. if the jumper repair works i might just go ahead and move my kiwi 120 km down the road to my parent's acreage where i probably can't make the same bone-headed mistake that far away
My antennas are not far away from each other (around 15 meters).
I installed this equipment on the Kiwi Rf in : https://fr.aliexpress.com/item/1005004883750098.html?src=google&src=google&albch=shopping&acnt=248-630-5778&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=UneMJZVf&gclsrc=aw.ds&&albagn=888888&&ds_e_adid=&ds_e_matchtype=&ds_e_device=c&ds_e_network=x&ds_e_product_group_id=&ds_e_product_id=fr1005004883750098&ds_e_product_merchant_id=5436066189&ds_e_product_country=FR&ds_e_product_language=fr&ds_e_product_channel=online&ds_e_product_store_id=&ds_url_v=2&albcp=20180143332&albag=&isSmbAutoCall=false&needSmbHouyi=false&gad_source=1&gclid=Cj0KCQjwjNS3BhChARIsAOxBM6pnA15SeQYbfy5Gl1QcQgdMUeoPq3CTtYo4aaorEnMH0Qt-xbSNfeUaAqOhEALw_wcB
and push all the buttons in order to get 90 db attenuation.
This not automatic and not very sexy but it works so far.
Added info : my transmitting power is 100 watts
This is the worst thing I have ever seen (related to Kiwi front-end damage).
Customer sends Kiwi back. Says it was installed at a remote location with other SDRs and no co-located transmitters. Died after a few weeks.
I open it up, start some measurements and see that three of the four 30 MHz LPF inductors are wrong. They're black instead of the blue ones from Murata we've specified in our bill-of-materials. So I immediately think the factory has substituted some cheap-ass parts. Then I measure an open circuit on one of them so I go very gently poking at it. And the black part in the center flakes off, exposing the windings underneath. And then it dawns on me what's happened: Those three inductors are burned up.
In the photo below (cellphone taken through a microscope) the burned inductors originally all looked like the one on the left. The two on the right have had the windings exposed. The right inductor had broken wire in the winding.
How can this possibly have happened? Everything else is intact (see schematic: kiwisdr.com/docs/KiwiSDR/kiwi-2.schematic.pdf) The two 100V series coupling caps ahead of the LPF are fine (not shorted, correct value). The TVS and GDT are fine (not shorted). The 100k ohm static bleed resistor is fine. Even the small value caps on the LPF are fine.
Was there a pulse of energy on the antenna so severe it caused the 3 of the 4 inductors to burn up like that? Like fuses? If it were a DC short somehow the 4th inductor should have showed similar damage I would think. Like if the attenuator failed and put 3.3V on its input. But there's no ground path anywhere. The LPF caps are 50V. The series caps are 100V.
We did have one person recently say a number of components failed on their Kiwi. Including the first LPF inductor (L401) and the ADC preamp. But the photo included only showed it post-repair (L401 pads bridged over). The other inductors looked fine.
I'm just really amazed by this.
I've seen lightning do "interesting" things, but in that case I would have assumed that the TVS diode would have done something.
Does the TVS diode become conductive at the design voltage? Maybe it can fail open.
Wow. I doubt a pulse. Not enough energy to do this and not a lot of other damage as well. Maybe high power RF directly injected though. High as on the order of watts not milliwatts and for long enough to cause the heating/burning you see. Almost any likely antenna-antenna pathloss likely more than 20 dB so I doubt over-the-air causation. Since the C's survive it doesn't seem to have been related to any DC component.
Maybe a chain of events, can't see the schematic since you provided the top of the hierarchy not the front end. Presuming LPF is in front of attenuator maybe L404 went first, why that could be the case possibly inferrable from a frequency of the destroyer conjecture, then followed by L401/402 , why not L403, can't say but schematic might give a clue.
Did a TVS survive?
can't see the schematic since you provided the top of the hierarchy not the front end.
Multi-page pdf -- should be able to just scroll down.
multi-page pdf, what will they think of next😀 How does one generate that, I've clearly been in KiCad too long and am out of touch with other tools!
But the fact that of series L's, one burns up while the other survives it gets really interesting thinking of a scenario that explains it. It may be that high power VHF/UHF and the SRF of the parts might have to be involved. Without looking at so-called 'parasitic' attributes it gets hard to explain doesn't it?
Fun.
Coil L403 has the lowest inductance of all four coils. Perhaps it is wound with thicker wire and therefore withstood the high current.
@studentkra Excellent point. The Murata specs do give nominal max current and series R values:
L401/404 330nH 85mA 5R5
L402 270nH 110mA 3R4
L403 150nH 160mA 1R5 (didn't burn up)
@n6gn I think the regular KiCAD "file => print" menu item does it. I can't quite remember. Pretty handy.
I like the fact you don't skimp on quality components, and won't use "compatible" ones based on cost. I used to sell electronic components in Auckland in the 80's, and it was a tough job convincing people to use quality Japanese components over cheaper (back then) Taiwanese parts - along with the very small manufacturing base in NZ and lots of suppliers.
Pretty good that the PE4312 survived (if it did), enough to cook inductors.