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Shuts down in 40m

 

Anyone had this issue.? Powered by a LiPo battery and using a 1/4 vertical with a wolf river coil with an swr less than 1.5.? When transmitting CW at 100 W, the unit will shut down.? If I turn down the power to 25 W this won't happen.? Doesnt happen on 20m. Any ideas?
 

Michael,

This appears to be a case of RFI.? Most likely coming from current traveling on the outside of your coax feedline back to the IC7000 which is causing the shutdown.? The amount of "common mode" current will vary by band and this is why it occurs on 40 m but not 20 m.? ?My first step would be to install a common mode choke at the base of the antenna.? Connect the output of the choke to the antenna and your feedline to the?input.? ? Changing the length of the feedline might help as well, but this would likely move the problem from one band to another.

Balun Designs manufactures?these devices.? ?My experience is that they make good products.? Here's a link:??

I have no affiliation with Balun Designs.

Good luck,

Robie AJ4F

On Mon, Feb 5, 2024 at 6:57?AM Michael Parker <miketparker@...> wrote:
Anyone had this issue.? Powered by a LiPo battery and using a 1/4 vertical with a wolf river coil with an swr less than 1.5.? When transmitting CW at 100 W, the unit will shut down.? If I turn down the power to 25 W this won't happen.? Doesnt happen on 20m. Any ideas?

 

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I would start with some ferrite but also try a dummy load at full power. If the radio shuts down then check the fuse holders by reseating both fuses. 73 GL

Feb 5, 2024 7:57:30 AM Michael Parker <miketparker@...>:

Anyone had this issue.? Powered by a LiPo battery and using a 1/4 vertical with a wolf river coil with an swr less than 1.5.? When transmitting CW at 100 W, the unit will shut down.? If I turn down the power to 25 W this won't happen.? Doesnt happen on 20m. Any ideas?

 

I have a. Choke on order.
 

Nott at home, so don't have a dummy load, but will try the ferrites.
 

Michael.....Icom radios are very voltage dependent...My 7000 will transmit with the truck shut off about two or three times for short periods, then the radio shuts down.
?? Cut the power to 30 or 40 percent and its all good......Run the engine while transmitting and there's never a problem at full power.
? I had the same issue with my? Ic 706, and an Icom dual bander in the mobile.? Awg 10 wire feeding the radios so plenty of cutrrent....
Stick a voltmeter inline and you will see the voltage drop....about the only thing you can do is operate at less than full power.
?Good Luck
Phil K2RRX

Sent with secure email.

On Monday, February 5th, 2024 at 7:57 AM, Michael Parker <miketparker@...> wrote:

Anyone had this issue.? Powered by a LiPo battery and using a 1/4 vertical with a wolf river coil with an swr less than 1.5.? When transmitting CW at 100 W, the unit will shut down.? If I turn down the power to 25 W this won't happen.? Doesnt happen on 20m. Any ideas?

 

I had this exact problem with my 7000 as well on 40m only. Turned out to be RF in the shack. In the days before I had proper 1:1 Current BalUns in the feed coaxes. The culprit turned out to be a secondary feeder used to connect a SDR to a different antenna conducting RF back to the shack via the outer face of the coax braid. The moment I slugged the cable with some clip on ferrite sleeves at the shack end and a BalUn at the antenna end the problem disappeared.
 

If it's indeed low voltage and not RFI, N8XJK (and others) make a 'voltage booster' that?may help.? When I was a sailboat liveaboard I used one while at anchor or under sail, essentially whenever not running engines.? Worked for my IC-7K.

73,

Bob, WB2DWD

On Tue, Feb 6, 2024 at 10:24?AM Al Browne <post2al@...> wrote:
I had this exact problem with my 7000 as well on 40m only. Turned out to be RF in the shack. In the days before I had proper 1:1 Current BalUns in the feed coaxes. The culprit turned out to be a secondary feeder used to connect a SDR to a different antenna conducting RF back to the shack via the outer face of the coax braid. The moment I slugged the cable with some clip on ferrite sleeves at the shack end and a BalUn at the antenna end the problem disappeared.

 

The 7K's aren't much more DC voltage dependent than any other mobile HF radio, IF the poorly designed fuse holders on the factory DC power cable are replaced with good quality 30 amp holders that bite through the fuse blades' surface oxidation that builds up over time.? Cleaning the fuse blades will help temporarily, but the fuse holders have an inherent design flaw, compared to typical automotive-style ATC fuse holders.? Of course there can be other sources of voltage drops that all add up in a mobile or battery-powered installation.? There should be less than 500 millivolts drop from the battery terminals to the TUNER port pins 3-4 under load in a proper installation.

A properly adjusted 7K will operate down to 10.9 VDC (as measured across the TUNER port pins 3-4 while transmitting with the TX PO=100%).? The output power will decrease by 50-60% compared to 13.8 VDC.

Below about 10.5 VDC the radio will do a reset of the CPU, mainly designed to protect the radio during a power-up cycle until the supply voltage is stable.? IC1301 is the reset control IC for the CPU.

Transmitting at 100W on just battery power (without the engine running) is not good practice.? Adding a battery booster just makes a bad situation worse for? battery life.? Dropping the TX PO to 50W only decreases the received signal by 3 dB, but can quadruple battery run time typically.

Steve, W3AHL
 

A common mode choke fixed the problem.? Tnx.
 

Michael,

Thanks for the feedback.? It's good to know what works!

73,

Robie AJ4F

On Sun, Feb 18, 2024 at 5:18?PM Michael Parker <miketparker@...> wrote:
A common mode choke fixed the problem.? Tnx.

 

Fo you know where I can get some quality fuse holders?
 

I cut off the OEM holders and use Power Poles, connect it to a Power Pole distribution box that has higher quality fuses.

73! Mark KA6WKE - DM34st
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On Sat, Mar 9, 2024 at 3:13?PM Michael Parker <miketparker@...> wrote:
Fo you know where I can get some quality fuse holders?

 
Edited

These are okay:??

Many automotive stores sell 30-amp rated ATO/ATC inline fuse holders, but most use 12 gauge leads, which I have found to often have poor quality contacts.? Littelfuse 30-amp heavy duty holders with 12 gauge leads seem okay though.? Search for Littelfuse FHAS100.

I like the MAXI 30-75 amp fuse holders, but the cost of the fuse holder & fuse is 3X+ that of the ATO/ATC style.

Replacing the fuse holders with PowerPole connectors and using a RigRunner to fuse the positive lead is okay for portable operation, but mobile installations should always have the ground/negative lead fused also, which a RigRunner distribution box doesn't do.? Plus, every crimp and connector adds voltage drop under high current peaks, so I feel it's better to go as direct as possible if you want to operate with the engine off or with a standalone battery for portable use.? ? ? ?

Steve, W3AHL
 

Having designed & built many mobiles, I placed ground & power fuses right at the battery, then off to the rig runners. This worked just?fine for large installs.




On Sun, Mar 10, 2024, 14:15 Steve W3AHL <w3ahl@...> wrote:
These are okay:??

Many automotive stores sell 30-amp rated ATO/ATC inline fuse holders, but most use 12 gauge leads, which I have found to often have poor quality contacts.? Littelfuse 30-amp heavy duty holders with 12 gauge leads seem okay though, but I haven't seen theirs with a protective cover for years.

I like the MAXI 30-75 amp fuse holders, but the cost of the fuse holder & fuse is 3X+ that of the ATO/ATC style.

Replacing the fuse holders with PowerPole connectors and using a RigRunner to fuse the positive lead is okay for portable operation, but mobile installations should always have the ground/negative lead fused also, which a RigRunner distribution box doesn't do.? Plus, every crimp and connector adds voltage drop under high current peaks, so I feel it's better to go as direct as possible if you want to operate with the engine off or with a standalone battery for portable use.? ? ? ?

Steve, W3AHL?

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