Reply
 
Thread Tools Search this Thread
 
Old 19 March 2006, 05:17   #1
Member
 
Country: Ireland
Town: Dun Laoghaire
Boat name: Ruby
Make: Valiant 490
Length: 4m +
Engine: Yamaha 60-4
Join Date: Mar 2006
Posts: 74
How hot does a fixed VHF get?

My current dinosaur of a VHF is in a box attached to the back of my rib's double jockey console, which is pretty useless for anything except emergencies. I want to have the new unit within convenient reach as I drive but the console is too small to fit any more kit onto it.

The only possible way I can see to install a new radio is to remove the first 4 inches of the jockey cushion (which is never sat on anyway), replace it with a horizontal console panel and drop the unit in vertically so that it's facing upwards.

However, that means the back of the radio is quite close to the fuel tank. And as all fixed VHF sets seem to have heat dissipating fins at the back, perhaps this isn't a very good idea. Does anyone know how hot a fixed VHF can get? I'm guessing the worst scenario is heavy use at 25 watts in a mayday situation. If I was already in trouble I wouldn't want to be worrying about blowing up the petrol tank as well!
__________________

__________________
jgrace is offline   Reply With Quote
Old 30 March 2006, 09:22   #2
Member
 
Country: UK - England
Town: Solent
Boat name: Hammertime
Make: 6.3 RIB
Length: 6m +
Engine: Mercury 115 Optimax
Join Date: Oct 2005
Posts: 10
If I were you I would save myself a lot of trouble and just get a hand held vhf!
__________________

__________________
archie720 is offline   Reply With Quote
Old 30 March 2006, 09:39   #3
Member
 
Country: UK - England
Town: Newquay, Cornwall.
Boat name: None :(
Make: None :(
Length: 5m +
Engine: None :(
MMSI: None :(
Join Date: Jun 2005
Posts: 1,280
Or do this - although I wouldn't recommend doing it with a Silva S10 like I did (they are not very waterproof) should be fine with a icom though.
Attached Thumbnails
Click image for larger version

Name:	DSCN0831 (Small).JPG
Views:	153
Size:	31.5 KB
ID:	18220  
roycruse is offline   Reply With Quote
Old 30 March 2006, 11:20   #4
Member
 
Country: Ireland
Town: Dun Laoghaire
Boat name: Ruby
Make: Valiant 490
Length: 4m +
Engine: Yamaha 60-4
Join Date: Mar 2006
Posts: 74
Quote:
Originally Posted by archie720
If I were you I would save myself a lot of trouble and just get a hand held vhf!
That would certainly make life easier, but I'm still kinda set on getting a fixed set. There's already a whip aerial on the boat, plus in the wide open spaces of the West coast 25 watts is somehow comforting.

Quote:
Originally Posted by roycruse
Or do this - although I wouldn't recommend doing it with a Silva S10 like I did (they are not very waterproof) should be fine with a icom though.
Very simple solution! Does it not get knocked, though?
__________________
jgrace is offline   Reply With Quote
Old 30 March 2006, 12:00   #5
DJL
Member
 
Country: UK - England
Make: Ribcraft 6.5
Length: 6m +
Engine: Suzuki DF175TG
Join Date: Apr 2002
Posts: 929
Handheld is ok, but reception isn't anywhere near as good as fixed.

You shouldn't have any problems with the radio that close to the fuel tank. The heat sink shouldn't get that hot, not any where hot enough to ignite petrol anyway (200 ish degrees).


Although if you blow yourself up don't blame me..
__________________
DJL is offline   Reply With Quote
Old 30 March 2006, 12:48   #6
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
Standard Horizon (if they're available over there) makes a "Black Box" VHF; you mount the black box inside somewhere, and the only thing exposed is the mike and cable (and antenna, of course.)

PS1000 and PS2000.

Probably other manufacturers have the same thing.

jky
__________________
jyasaki is offline   Reply With Quote
Old 30 March 2006, 13:17   #7
Member
 
Country: Ireland
Town: Dun Laoghaire
Boat name: Ruby
Make: Valiant 490
Length: 4m +
Engine: Yamaha 60-4
Join Date: Mar 2006
Posts: 74
Quote:
Originally Posted by DJL
You shouldn't have any problems with the radio that close to the fuel tank. The heat sink shouldn't get that hot, not any where hot enough to ignite petrol anyway (200 ish degrees).


Although if you blow yourself up don't blame me..
I won't. I'll just haunt you

Actually, I met an old salt a couple of days ago who also told me that a bit of heat near the fuel tank is OK. He was more concerned about static discharge, saying I should make sure that petrol fumes can't get to the radio or the line to the aerial.
__________________
jgrace is offline   Reply With Quote
Old 31 March 2006, 03:44   #8
Member
 
Cookee's Avatar
 
Country: UK - England
Town: Salcombe, Devon, UK
Boat name: BananaShark
Make: BananaShark
Length: 10m +
Engine: 2xYanmar 260 diesels
Join Date: Mar 2003
Posts: 4,225
Simrad do a black box radio for the UK market - a little expensive though! Icom are just about to bring out a unit that is fully controllable from the handset which would be a cheaper option.
__________________
Cookee
Originally Posted by Zippy
When a boat looks that good who needs tubes!!!
Cookee is offline   Reply With Quote
Old 31 March 2006, 04:19   #9
Member
 
Country: Ireland
Town: Dun Laoghaire
Boat name: Ruby
Make: Valiant 490
Length: 4m +
Engine: Yamaha 60-4
Join Date: Mar 2006
Posts: 74
The Standard Horizon and Simrad black boxes look very interesting - I didn't know that format existed - but for better or worse I've already ordered an Icom M-421.

Roycruse's external mounting is the simplest option for my situation, but I'm considering a slightly raised console panel to give me a couple of inches clearance between the back of the vhf and the fuel tank. I need a new panel anyway coz I've got to cut into the old one to get the new bigger fuel tank in.
__________________
jgrace is offline   Reply With Quote
Old 31 March 2006, 05:03   #10
Member
 
Country: UK - Scotland
Make: HumberOceanOffshore
Length: 8m +
Engine: Volvo KAD300/DPX
Join Date: Oct 2002
Posts: 4,962
Quote:
Originally Posted by jgrace
.. ..Does anyone know how hot a fixed VHF can get?
From memory, the typical maximum junction temperature of a transistor is about 120c and it is good practice to design to limit the temp to about half of that. I would reckon on it getting warm only after prolonged Tx.
__________________

__________________
JW.
jwalker is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 07:29.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.