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Help Identifying Peter Dahl ALS4T Custom transformer specs

 

Greetings to the Group,
?
? ? I bought a Peter Dahl transformer for use in a 1296 MHz tube amp using 2C39/7289's.? The P/N on the transformer is ALS4T and the serial number is 06/14/01.? Albeit a custom transformer (as I believe most were), I recall this being in his catalog.? However, the ones that I can find (mid 2000's from Harbaugh) do not have it.? Might someone in the group have something earlier than this that might have it in the price description pages?? Modest in size, it is a hypersil design with a 110/220v primary, 6.3v filament, and a HV with C.T.? I'm trying to figure out the HV secondary ratings.? Peter Dahl P/N ALS4T.??
?
? ?Thanks in advance.
?
73, Mike K9MK
?
?
?
 

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I sent you a copy of a 2008 catalog I have.

It not obvious how to upload this to the Files section of the forum.? I’ll sent a copy to somebody who can upload this to the Files section for this forum.

?

73,

Dave, w6de

?

From: ham-amplifiers@groups.io <ham-amplifiers@groups.io> On Behalf Of K9MK via groups.io
Sent: 15 November, 2024 02:52
To: ham-amplifiers@groups.io
Subject: [ham-amplifiers] Help Identifying Peter Dahl ALS4T Custom transformer specs

?

Greetings to the Group,

?

? ? I bought a Peter Dahl transformer for use in a 1296 MHz tube amp using 2C39/7289's.? The P/N on the transformer is ALS4T and the serial number is 06/14/01.? Albeit a custom transformer (as I believe most were), I recall this being in his catalog.? However, the ones that I can find (mid 2000's from Harbaugh) do not have it.? Might someone in the group have something earlier than this that might have it in the price description pages?? Modest in size, it is a hypersil design with a 110/220v primary, 6.3v filament, and a HV with C.T.? I'm trying to figure out the HV secondary ratings.? Peter Dahl P/N ALS4T.??

?

? ?Thanks in advance.

?

73, Mike K9MK

?

?

?
 

Contact Dahl / Hammond.

You could also feed 10 vac into the primary and measure the secondary,? to calculate the turns ratio.?


The SN on the Dahl label is NOT a SN, it's the date code !?
 

On Fri, Nov 15, 2024 at 08:14 PM, Dave w6de wrote:

<It not obvious how to upload this to the Files section of the forum.? I’ll sent a copy to somebody who can upload this to the Files section for this forum.

If it's a PDF or similar it's easy to upload to the files section.? You cand send it to me or dino if u want, and we can upload it to the files section.? ?We are both admins of this group, but anybody can upload files, pix etc.? ?
 
Edited

Hi Mike,

I have a transformer that was bought (by me) from Dahl some years ago, intended to power a 6x7289 ring amplifier for 1.2 GHz (750W out) built at about the same time by KB2AH (edit the info with the RF deck specified 1650V 1.8A supply capability, reflected in the requirements given to Dahl at the time for build of the HV transformer noted below below.)

The transformer has no part number (it was custom built at the time) but has the following properties (on it's label and on the screw terminals at the top of the transformer.)

Hypersil design
Primary Volts 0 - 230V - 240V
Secondary Volts 0 - 1150V - 1200V - 1250V - 1300V - 1350V
Secondary current 1.8A CCS (hence probably 2.5 KVA CCS)
(edit) Serial Number (possibly date of manufacture?) is 121597 (Dec 15 1997? not sure if this is how Dahl issued serial numbers.)

I don't have a weight or dimensions right now (I could gather either/both if it would be helpful for you).

The data received from Peter Dahl has probably been lost to the ages, but the transformer's labeling is clear as it's still new and has been in a benign environment since purchase.

(edit 2) - Found in the section '1' of the Peter Dahl catalog uploaded by VE7RF the following, which seems pretty similar (but not identical) to the transformer here:

1300/1175/1050/925V @ 2A CCS
1296 MHZ EME AMP POWER SUPPLY XFMR
CORE) A-0480/ C-CORE STYLE #) 10 HIPERSIL C-CORE
PR) 234 VAC 60 HZ 1 PH
S1) 0-925-1050-1175-1300 VAC @ 2.0A CCS
DM) HT = 8.625 WT = 8.075 DT = 7.688 MD = 3.937 MW = 5.500
PRICE) $350.00 Plus S&H FOB El Paso, TX WEIGHT) 46 LBS

As this transformer wouldn't fit the criteria of modest size as you describe yours, I doubt they are the same, and I never followed up to see if this transformer's spec became anything of a catalog product, but perhaps this info will be useful to you.

73 Dave WB0GAZ wb0gaz@...
 

Thanks to everyone that replied here and privately too.
Next, I must apologize for a partial goose chase and get an appointment at the eye doctor!
The transformer plate below clearly shows I obviously read the 8 as an "S".? ? ?
?
It's an AL84T
?
And yes, the date code is stamped in the serial number space.
?
As suggested, I plan to run this up to 10V on the bench and check the secondary.
?
Thanks All!? ? ? ?73, Mike K9MK
?
PS: This is a smaller form factor. IIRC about 6" on a side, more or less.??
?
?
 

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Here’s from the original PWD catalog:

?

?

PRIME INST P/N AL84T

?

CORE) A-0016/ C-CORE???????? STYLE #) 10? HIPERSIL C-CORE

PR) 117/234 VAC 60 HZ 1 PH

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S1) 0-600-850 VAC @ 1.0A ICAS

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S2) 6.0 VAC @ 8A CCS

?

DM) HT =? 5.750 WT =? 6.200 DT =? 5.000 MD =? 3.125 MW =? 4.000

PRICE)??? $225.00 Plus S&H; FOB El Paso, TX??? WEIGHT)?? 17? LBS

?

Mod-U-Lator,

Mike(y)/W3SLK

?

?

?

From: ham-amplifiers@groups.io [mailto:ham-amplifiers@groups.io] On Behalf Of K9MK
Sent: Saturday, November 16, 2024 9:45 AM
To: ham-amplifiers@groups.io
Subject: Re: [ham-amplifiers] Help Identifying Peter Dahl ALS4T Custom transformer specs

?

Thanks to everyone that replied here and privately too.

Next, I must apologize for a partial goose chase and get an appointment at the eye doctor!

The transformer plate below clearly shows I obviously read the 8 as an "S".? ? ?

?

It's an AL84T

?

And yes, the date code is stamped in the serial number space.

?

As suggested, I plan to run this up to 10V on the bench and check the secondary.

?

Thanks All!? ? ? ?73, Mike K9MK

?

PS: This is a smaller form factor. IIRC about 6" on a side, more or less.??

?

?
 

From the part number AL84T (and mention of "Prime", which was a predecessor to Ameritron) in the Dahl catalog pages that were uploaded and cited here, your transformer appears to be a replacement transformer for the Ameritron Al84 (four sweep tube, HF) amplifier.

Sweep tubes in this sort of amplifier often run about 1kv on the plate (others here can almost certainly clarify/correct.)

A quick perusal of some 7289 (2C39) type 23cm PA projects seems to recommend 1200-1400VDC on the plate(s), so your transformer might yield at the low end of that range if you use the higher-voltage secondary tap (850 VAC * 1.4).

Best of luck on your project and welcome to 1296!

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