[Amps] Peter Dahl transformers

Fri Feb 15 20:15:15 EST 2013

I am sure that most of the RTTY contest community is happy that this mode 
has not grabbed your fancy.  But if you ever do decide to RTTY contest, 
Carl, that LK800 is a real sweet amp.  Even if Jim would consider it worth 
of being an exciter-category amp only.

73/jeff/ac0c
www.ac0c.com
alpha-charlie-zero-charlie

-----Original Message----- 
From: Carl
Sent: Friday, February 15, 2013 6:47 PM
To: Jeff Blaine ; amps at contesting.com
Subject: Re: [Amps] Peter Dahl transformers

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
>>>> _______________________________________________
>>>> Amps mailing list
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>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>
>>>
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