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Icom 7300
#1
If you own an Icom 7300 you may want to bin it after watching this video:
https://youtu.be/EmfRzqhONyo
John VA3KOT
Blog: HamRadioOutsideTheBox.ca
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#2
IC-7300 week at GBARC, I presume?

Modern rigs are typically specified for 13.8 ± 15% VDC supply, i.e. 11.7 - 15.8 V.  But, I've read many forum posts where owners of various brands were reporting various kinds of misbehaviours when the supply voltage is low. 

The IC-7300 CW splatter in the video is especially worrisome.  I wonder what happens on SSB?  

Portable ops on an SLA battery would be problematic due to the rapid drop in voltage with discharge.  A LiFePO4 would be much better.  You can find lots of data showing how the LiFePO4 holds its voltage nearly constant up to very deep discharge. 

Another solution would be a DC booster like the MFJ-4416.  Here's a link to a review by Phil Salas AD5X that was published in QST:
http://www.ad5x.com/images/Presentations...16RevB.pdf

But, if anyone intends to "bin" their IC-7300, they can give it to me - I promise to supply it with enough voltage :-)

73
Dave, VE3WI
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#3
Thanks for the link to the MFJ voltage booster review Dave. I do a lot of portable ops in the summer and I just switched to an LFP battery from an SLA. I use a Yaesu FT-891 when portable so I will have to test it to find out what it's output is like during low voltage conditions.

I also own an FT-817 QRP rig (the original model bought in 2001) and that would operate down to around 9 volts!
John VA3KOT
Blog: HamRadioOutsideTheBox.ca
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#4
(2021-03-06, 19:56:58)VE3WI Dave Wrote: IC-7300 week at GBARC, I presume?

Modern rigs are typically specified for 13.8 ± 15% VDC supply, i.e. 11.7 - 15.8 V.  But, I've read many forum posts where owners of various brands were reporting various kinds of misbehaviours when the supply voltage is low. 

The IC-7300 CW splatter in the video is especially worrisome.  I wonder what happens on SSB?  

Portable ops on an SLA battery would be problematic due to the rapid drop in voltage with discharge.  A LiFePO4 would be much better.  You can find lots of data showing how the LiFePO4 holds its voltage nearly constant up to very deep discharge. 

Another solution would be a DC booster like the MFJ-4416.  Here's a link to a review by Phil Salas AD5X that was published in QST:
http://www.ad5x.com/images/Presentations...16RevB.pdf

But, if anyone intends to "bin" their IC-7300, they can give it to me - I promise to supply it with enough voltage :-)

73
Dave, VE3WI

In the past my IC-7000 would be fine to ~10VDC on SSB but I haven't done any operating on CW on batteries. I imagine on CW it would probably pull the voltage down below the cut-off point. I think Icom manual said 10.5 vdc for minimum operating voltage. I will have to try it next time I go portable.
Here is an Amazon link for voltage regulator more affordable than MFJ for $40 CAD. As long you don't have to carry all that portable stuff on a hiking trip  Cry then might be better to just go with a QRP rig that operates between 8 - 14vdc. Idea Few of them out there.
https://www.amazon.ca/Converter-DROK-Tra...NWZY&psc=1
For another $25  you can add this multimeter.
https://www.amazon.ca/DROK-Multimeter-6-...ZJN7EAWMD8
73, Adam ve3fp
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#5
The DROK could be the basis for a cheap & workable unit, with a box, connectors, etc.  I wonder how RF quiet it is.  Reviews of the MFJ-4416 talk about some RF noise.  Adam, why don't you buy one & test it for RFI?

The only competition in the ham area that I know of for the MFJ is the N8XJK booster.  His company went belly-up a while ago but West Mountain Radio is going to start selling them, according to their website.  It got good reviews when it was on sale.  It's pricier than the MFJ: $250 US vs $200.  For that much money, I would rather buy a solar panel to keep the battery topped up.

I have a 15 ah LiFePO4 battery that will run my little Xiegu X108 xcvr for hours.

73
Dave, VE3WI
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#6
(2021-03-07, 20:04:29)VE3WI Dave Wrote: The DROK could be the basis for a cheap & workable unit, with a box, connectors, etc.  I wonder how RF quiet it is.  Reviews of the MFJ-4416 talk about some RF noise.  Adam, why don't you buy one & test it for RFI?

The only competition in the ham area that I know of for the MFJ is the N8XJK booster.  His company went belly-up a while ago but West Mountain Radio is going to start selling them, according to their website.  It got good reviews when it was on sale.  It's pricier than the MFJ: $250 US vs $200.  For that much money, I would rather buy a solar panel to keep the battery topped up.

I have a 15 ah LiFePO4 battery that will run my little Xiegu X108 xcvr for hours.

73
Dave, VE3WI

I don't think I will be doing any battery field operating in the near future. I will drive to the site and use the generator or better yet operate from camper trailer plugged into conventional power or generator. 
Didn't see any reviews on those DC - DC units just what's on Amazon.
73, Adam ve3fp
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