https://www.ebay.com/itm/254375574086
Something like this. But I would need for it to handle 23 amps
Something like this. But I would need for it to handle 23 amps
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Radio requires 13.8 volts, I only have a 12 volt battery system
- Thread starter old goat 321
- Start date
I have a local friend who has the voltage issue with his ICOM 7000 & I believe the voltage booster was his fix.Anytime he stopped the car for any reason the voltage would drop so he sounded distorted on his transmit audio.He had the car worked on several times & a new battery & alternator replaced & still had the same issue.He no longer has the issue with the voltage booster so it fixed the drop in voltage to the IC-7000.
SIX-SHOOTER
Only way to know for sure is to measure it, unless the manufacturer tells you the answer.
100w / 13v is 7.7 amps. Have to factor in efficiency...which is almost certainly higher at full output than it is at QRP levels. 50 % efficiency would double the ampere draw...15 and change.
I suspect it’s not 23 amps with a carrier, however. Your radio shouldn’t do a 100w carrier. I’d imagine that 23 amps is probably max ampere draw on AM mode.
100w / 13v is 7.7 amps. Have to factor in efficiency...which is almost certainly higher at full output than it is at QRP levels. 50 % efficiency would double the ampere draw...15 and change.
I suspect it’s not 23 amps with a carrier, however. Your radio shouldn’t do a 100w carrier. I’d imagine that 23 amps is probably max ampere draw on AM mode.
I'm a little confused with the carrier signals. The owners manual says Tx (100watts) .. 23 amps. Geeze, what could draw 23 amps at 100 watts? Reason I'm asking is I found a quality converter that will give out 13.6 volts. Max of 15 amps. I think its output is 200 watts. I dont use am. I do use ssb and digital on ft8. I also use winlink. But I believe that is usb also. I'm wondering if 15 amps would be enough for my needs
I don’t think it’s enough...but there’s simply no way for me to know for sure.
The efficiency of the transceiver and the duty cycle of the device at full output would be absolutely critical to making an informed decision.
Absent that, overkill is the only answer. If I went that route (and I would) I would personally be trying to find a device that could supply 150% of the rig manufacturer’s rated max ampere draw...or 35 amps.
Not because it’s totally necessary, but because it’s how I think.
The efficiency of the transceiver and the duty cycle of the device at full output would be absolutely critical to making an informed decision.
Absent that, overkill is the only answer. If I went that route (and I would) I would personally be trying to find a device that could supply 150% of the rig manufacturer’s rated max ampere draw...or 35 amps.
Not because it’s totally necessary, but because it’s how I think.
I'm a fan of overkill as well. I would rather to have it and not need it than need it and not have it
I assure you that my ICOM 7600, ICOM 746,& ICOM 910H will all dead key 100 watts or more and do 100 watts on Peaks on SSB as well as designed.All of them pull over 20 amps on peaks as well.I have never owned any 100 watt HF Radio that did not do 100 watts on FM or SSB since 1994.I like using FM Repeaters across the country when the 10 meter and 6 meter bands are open because it’s just different from the same bunch that you find on SSB & AM.The AM carrier is usually anywhere from 25 to 40 watts on AM on most HF radios.
SIX-SHOOTER
I don’t doubt you at all...but the AM carrier is what I was referring to. I think most 100w rigs do not have a carrier that high?
I’m ok being wrong though, as is definitely applicable from time to time.
Saved me the trouble CK.
I have 165' of CAT-6e POE (power over ethernet) going to a Ubiquiti NS2 that requires at least 11.8V. POE injection voltage is 32V to get 12.8v at the other end.
I have several Icom IC-735's that are aligned and tuned at 12v. Apply 14v to them and they act like they have a turbocharger and NOS hung on them. Tune them up at 14v and supply them with 12v and they barely run.
I too have a FT-857D. What a power hog. I not only upgraded the power wires but did away with the fuse holders and use a fast voltage/current trip normally seen in aircraft use. Just changing the DC feed to 10ga got a significant increase. The fuses may be good protection but are a choke point.
CK used published and well known wire tables for resistance and voltage drop. These calculators can be found all over the interwebz. It's not rocket surgery, just math.
Now a bit of a gotcha. The boost converters easily available and all over China-bay are in a word "noisy". For marginal DC runs and limited current drain they may work. Leave them on in receive and watch the noise floor . The limited input filtering (usually just a small choke/cap input) of the radio can't filter out the hash on the DC input and it shows up on the transmitted signal as well. Not only does the hash from the converter end up on the signal but some digital radios have a fit over the dirty power and exhibit it in what can only be called "gremlins" .
Practical solution:
Make the battery bank at least 18v (24v may be better) and use a linear regulator at the source (the battery bank) that produces 14v at the sink (radio or other device). You still have the resistance and voltage drop but you have what you need in (at) the end, and you don't have to suffer the square wave hash of a switching regulator.
Not sold in stores
YMMV
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Only your electrical engineer knows for sure
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Also not all batteries are created equal. Deep cycle batteries do not have a very good surge capacity. I had a huge battery that would not start my riding lawn mower. But a smaller motorcycle battery cranked it right up.
Both batteries were made for different purposes. Deep cycle will put a certain amount of current out for a long period of time but do not have a large surge current capacity.
You could make a large capacitor bank right behind the radio.
Both batteries were made for different purposes. Deep cycle will put a certain amount of current out for a long period of time but do not have a large surge current capacity.
You could make a large capacitor bank right behind the radio.
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I don’t doubt you at all...but the AM carrier is what I was referring to. I think most 100w rigs do not have a carrier that high?
I’m ok being wrong though, as is definitely applicable from time to time.
As I stated in my last post,Most all HF Radios have an AM Carrier from between 25 to 45 watts.I don't know of ANY that have more than that.Most 25 watts Carrier & even the 200 watt radios such as the ICOM 7800,7810,Kenwood 990 & Yaesu FT-5000 don't have a 100 watt carrier on AM.
SIX-SHOOTER
I understand. I think we were just dealing with a disconnect on terminology.
I have no doubt the rig needs as much power as the manufacturer states.
In this particular case, I’d be very hesitant to run SSB with a setup like referenced, even with regulation at the source, because the voltage will be all over the map as the current demands change with modulation. Might be able to make something work that would keep it within specified +/- range, but I wouldn’t be happy with it unless regulated at the load.
Anxious to see how it works out for the OP.