HF radio

Submitted: Monday, Mar 08, 2010 at 09:51
ThreadID: 76667 Views:2790 Replies:3 FollowUps:0
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We have a codan 8525 HF radio & need to know the exact start up current when the radio is first turned on. I have fitted a voltage converter with 10amp output but when the codan is turned on the converter drops out & then resets immediately. This goes on & on as I assume the capacitors in the unit have a high in rush current. The unit works perfectly on the 12volt supply & yes I have contacted codan but as yet have had no reply ( a month ago). Hoping someone out there can help with this problem. Regards Aussie Noel.
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Reply By: Member - John and Val - Monday, Mar 08, 2010 at 10:09

Monday, Mar 08, 2010 at 10:09

We run this radio too - good gear.

I assume you're running from a 24V supply via a 12V adapter.

There will be capacitors drawing big current momentarily and tripping the adapter when first turned on. The actual current will vary depending on the installation, and it's only high for a very brief period so it isn't possible to accurately determine it. A possible solution would be to fit a high current NTC thermister in the 12V supply line - these introduce a small resistance when cold, dropping to a very low value as they heat up a little.


J and V
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AnswerID: 407817

Reply By: Ozhumvee - Monday, Mar 08, 2010 at 10:45

Monday, Mar 08, 2010 at 10:45
A voltage converter will not run a full power (100watt) HF unless it is rated at about 50 amps continuous and then you may still have problems.
I used to install them in everything from 4wd's to trucks and buses.
The radios requires about 25 amps on a peak to work satisfactorily when transmitting. We always fitted a large cartridge type fuse rated at 32 amp which Codan supplied as part of the install kit.
You also need to install the supplied power cable direct to the battery to avoid voltage drop on the peaks which are of very short duration as you speak.
The HF uses so little power in standby or when receiving that most just connect it across one of the 12v batteries direct, which while it will eventually kill that battery may take some time.
A better way is to fit a charge equaliser which floats both batteries in a 24v system at the same potential allowing you to draw as much 12v from either battery without harm.
There are also battery to battery chargers which do a the same or similar as well these days, best talk to Redarc or GSL for the latest info.
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Reply By: olcoolone - Monday, Mar 08, 2010 at 11:05

Monday, Mar 08, 2010 at 11:05
On standby you could expect up to 5 amps.

On voice you could expect 15 to 20 amps.

On selcall you could expect 20 to 25 amps.

If the voltage reducer is cutting out on receive only I would suggest rechecking your wiring and or the voltage reducer.

What model is your voltage reducer.

Make sure the voltage reducer is not designed for lights only.

Voltage reducers designed for aux equipment switch DC and most voltage reducers designed for lights switch AC.
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