[Amps] Peter Dahl transformers

Fri Feb 15 19:47:25 EST 2013

I dont consider ham RTTY contesting nor old buzzard AM linear transmissions 
true CCS. RTTY doesnt interest me and has never been used.

A  HB Class C AM amp and modulator here uses Gates 1000W carrier iron 
thruout and casual use at that level doesnt even faze it and helps hold the 
house down.

I do a fair amount of AM with a LK-500ZC/TS-950SD combo and the external 
Dahl is listed in ads as 1.7A CCS since it is a dual voltage and used for 
the LK-500/550/800/780 family. It never gets above room temperature at about 
400W carrier.

OTOH when I test a LK-800 with 3CPX tubes on the HV tap (2850V full bore) on 
AM it does warm up a bit at a 1000W carrier and after an evening of yakking 
but still far from uncomfortable.  It certainly gets thru slopbuckets trying 
to enroach!

Carl
KM1H

----- Original Message ----- 
From: "Jeff Blaine" <keepwalking188 at yahoo.com>
To: <amps at contesting.com>
Sent: Thursday, February 14, 2013 1:50 PM
Subject: Re: [Amps] Peter Dahl transformers

> He eventually called the one I bought 1.4 KVA CCS.   I draw about 1800 KVA 
> from it in RTTY contest duty and the surface temp of the core never gets 
> over about 45c.
>
> In fact, I was worried about the tradeoff of a high temp rise spec and 
> even with the 200C components used, figured keeping an eye on the core 
> temp would be a good idea.  So I had him build inside a thermistor which I 
> had measured R vs. temp before hand.
>
> But the transformer never warmed up as much as the "CCS" model forecasted 
> and I never implemented the temp monitor.
>
> Even for RTTY contest duty, what guys probably "need" out of a transformer 
> is what we called ICAS 5/5 back in the day.  That core takes a lot longer 
> than 5 minutes to cool down very much and it seems to me that it's a more 
> applicable spec unless you are an AM or RTTY rag chewer where you like to 
> ramble on for 30 minutes at a stretch.
>
> 73/jeff/ac0c
> www.ac0c.com
> alpha-charlie-zero-charlie
>
> -----Original Message----- 
> From: Carl
> Sent: Thursday, February 14, 2013 12:36 PM
> To: Jeff Blaine ; amps at contesting.com
> Subject: Re: [Amps] Peter Dahl transformers
>
> Yep, there is commercial CCS and ham/CB CCS; a big difference in weight 
> and
> price.
>
> There isnt a ham amp on the market that would survive commercial CCS at 
> its
> power capability.
>
> Carl
> KM1H
>
>
>
>
> ----- Original Message ----- 
> From: "Jeff Blaine" <keepwalking188 at yahoo.com>
> To: <amps at contesting.com>
> Sent: Wednesday, February 13, 2013 2:42 PM
> Subject: Re: [Amps] Peter Dahl transformers
>
>
>>I had a custom done by EPD.  He will build exactly what you want.  You can 
>>have complete control over the compromises and material set, if you know 
>>what you want specifically.
>>
>> He told me once that most guys start out talking about CCS specs but when 
>> the size and price come into focus, they start backing off from that.
>>
>> 73/jeff/ac0c
>> www.ac0c.com
>> alpha-charlie-zero-charlie
>>
>> -----Original Message----- 
>> From: Carl
>> Sent: Monday, February 11, 2013 8:17 PM
>> To: Paul Christensen ; amps at contesting.com
>> Subject: Re: [Amps] Peter Dahl transformers
>>
>> While I dont doubt that I see a large number of CB transformers and Im 
>> sure
>> a number of  super power hams also. The giveaway that these are not for
>> commercial use is the single phase construction no matter what the kVA
>> except for 2 listed and one is for CB mobile use. He is also not shy 
>> about
>> it either and shows a photo.
>>
>> The ICAS ratings vs weight is also interesting and even less than OEM in
>> Heath, Dentron, etc, and I do not see a Style description listed.
>>
>> Carl
>>
>>
>>
>>
>> ----- Original Message ----- 
>> From: "Paul Christensen" <w9ac at arrl.net>
>> To: <amps at contesting.com>
>> Sent: Monday, February 11, 2013 2:03 PM
>> Subject: Re: [Amps] Peter Dahl transformers
>>
>>
>>>A few months ago, EPD was highly recommended to me by Reid Brandon when 
>>>he was still with Eimac.
>>>
>>> Paul, W9AC
>>>
>>> ----- Original Message ----- 
>>> From: "Coffey" <coffey at starfishnet.com>
>>> To: <amps at contesting.com>
>>> Sent: Sunday, February 10, 2013 3:04 PM
>>> Subject: Re: [Amps] Peter Dahl transformers
>>>
>>>
>>>> Have no fear about Harbach not making transformers.  My friend Peter 
>>>> Eggimann has been making HV transformers since 1983 and has all the 
>>>> Dahl’s data and specs from years  ago. He has a nice manufacturing 
>>>> facility in Wendell, N.C........EPD    ....Electronic Products Design, 
>>>> Inc......website: epd-inc.com. I was a customer before I retired and 
>>>> now as a hobby amp builder.......Gary, K4AVC
>>>> _______________________________________________
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>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>
>>>
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