[UK-CONTEST] Small generators for portable stations

[Steve Knowles]

Hello Tim

The Addiscombe ARC has used a 2.6kW Tecumseh genset for the best part of ten 
years with no problems.  It has the usual (primitive) voltage regulation 
system but this has never caused problems.  The waveform is less than 
perfect, particularly at low loads, and we have found it necessary to apply 
a base load (up to 400W of lightbulbs) to prevent the UPS operating all the 
time.  However, with the base load on, the regulation is more than adequate 
for all requirements of a normal HF NFD (100W) station.

The major problems (in common with similar Briggs & Stratton powered sets) 
are that the fuel tank is very small (less than 4 hours capacity, although 
this can easily be remedied by using an outboard tank from a motorcycle or 
similar) and that the engine is splash lubricated - the sump capacity is 
very small and the oil needs topping up every 8 - 12 hours, necessitating an 
engine stop (hence the UPS).

We have tried smaller generators (<2kVA) but find that, although 
satisfactory on a steady load, they have trouble coping with a rapidly 
changing load and do not have the capacity to be adequately base-loaded 
while still handling the station.

I tend to concur with Ken, G3LVP, that you will probably do best if you can 
base your operation on a 12V battery-buffered supply, in which case a truly 
rubbish generator will do you FB!

73

Steve
G3UFY



----- Original Message ----- 
From: "Tim Hugill" <tim04 at swandhams.com>
To: <uk-contest at contesting.com>
Sent: Friday, July 30, 2010 5:34 PM
Subject: [UK-CONTEST] Small generators for portable stations


(I've only just discovered this list, thanks to Pete G4CLA, so apologies if
this have been discussed before.)

Having just got G4FJK back on the air again, I'm planning to get out
/Portable on 50 & 70MHz in the South West.
The station will be relatively modest, working out of the back of a Land
Rover.

I need to either hire or buy a suitable generator, but I'm not sure how
careful I should be in selecting which one.
And I am also trying to keep a cap on the financial outlay.
At the 2.5-3.0 kVA power level,  the choices appear to revolve around
1) Whether or not to choose one with a Honda engine for reliability, and
2) Whether to choose one with an AVR built in.

Trade hire centres seem to have only non-AVR gennies available, which would
be fine for a weekend of DIY tools, but perhaps not so kind on my new Yaesu
rig.
Looking to buy new, there are cheaper options available (£250-300) with or
without AVR, or the Honda (higher quality ?) options with AVR options and
high prices to match.
I'm hoping the answer will be to get a low-cost unit with a reliable engine
and long-run tank, but I'm looking for guidance.

Looking at the list of contributors to this site, none of you have won many
contests without a reliable power source.
So hopefully someone can offer some advice, which will probably be obvious
if I'd thought about it a bit longer, and for which I will be very grateful
!

(Another solution would be if someone has a suitable generator that they
would be prepared to part with for a sum.)

Many thanks

Tim Hugill
G4FJK

_______________________________________________
UK-Contest mailing list
UK-Contest at contesting.com
http://lists.contesting.com/mailman/listinfo/uk-contest