Hi Ulf,
To me the choice depends on how much you trust Company B. If Company B can be
trusted to meet their quoted specifications (2000VA with 2.5% voltage drop at
full load), then I'd go with them. As you note, 11 kilo is as big or bigger
than the transformers in many ham-rated commercial amps of the same power
rating. If you're planning on heavy contest use, or RTTY service, then Company
A is probably the better choice, but for routine ham operation I'd think
Company B makes mores sense, considering the large price differential. An
interesting choice.
73,
Jim W8ZR
> -----Original Message-----
> From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Ulf (SM0NOR)
> Sent: Monday, March 04, 2013 4:29 AM
> To: amps@contesting.com
> Subject: [Amps] Transformer choice
>
> Hi Guys,
> I'm looking for some feedback on two transformer offers I have. I'm intending
> to build a
> table top amp, so I'm accepting some compromises regarding the transformer. I
> have made
> inquiries to a couple of winders and I have boiled them down to 2 offers. I
> was asking for
> 2000 Volts @1A =2000VA (+ G1 and G2 windings). I'm targeting to get 2200-2400
> watts
> output in PEP service and about 1K in continuos service.
>
> Both companies claim 2000VA but at different core weights
>
> Company A:
> 17 Kilo toroid, D=200 mm, H=110. About 3% voltage drop at full load. Max
> temp rise =
> 105C over 40C ambient. DC resistance, about 25 ohms.
> Price: €480
>
> Company B:
> 11 kilo toroid, D=180 mm, H=85mm. About 2,5% voltage drop at full load.
> Can't, or don't
> want to specify other data.
> Price: €195
>
> So what are your reflections? The A is obviously a the better choice. They
> are serious and
> they offer detailed specs, exact delivery times etc. But all comes at a
> premium price.
> Company B is smaller and they obviously compromises with their
> specifications, but the
> price is a lot lower and so is the weight.
>
> Now, I don't expect the cheaper and smaller core to do wonders. The bigger
> one will for
> sure be more rugged and closer to "true 2000VA", especially if I run it in
> true continuous
> mode. I'm inclined to go for the the bigger one, because I want the best. But
> OTOH, I don't
> want to waste money because of a "feeling". Perhaps the smaller one will be
> enough given
> the table-top size/PEP service I'm targeting? After all, it matches what's
> inside most
> commercial amps in this category.
>
> I'm happy for any feedback...
>
>
>
> 73's
>
> Ulf (SM0NOR)
> ulf@sm0nor.com
>
>
>
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