PA3CLQ's Leuke Linken Nr. 434

 

How do you like the Virtual Tour on the USS Albacore AGSS 569? from PLL Nr. 431

http://ussalbacore.org

http://ussalbacore.org/html/virtual_tour.html

 

 

REM : 

I don't know about NSS, but part of my practice for 20WPM was QSX NMN/NAM/NAR WX BCST's.

I still miss NUKO NUKO NUKO.

If you miss or completely missed the era of shortwave CW, some consolation is upcoming in the next few weeks.

http://www.radiomarine.org/

Steve N8CPA

 

Beste mede amateur,

Dear fellow amateur,
In deze mail staat een link waarop het vierentwintigste DKARS-Magazine is te downloaden.

This mail contains a link which the 24th- DKARS-Magazine is available for download.
De Dutch Kingdom Amateur Radio Society is een stichting die de belangen wenst te behartigen van ALLE radioamateurs binnen het gehele Koninkrijk der Nederlanden.

The Kingdom Dutch Amateur Radio Society is an organization that seeks to represent the interests of ALL radio amateurs throughout the Kingdom of the Netherlands.
Namens de Dutch Kingdom Amateur Radio Society wens ik je veel leesplezier nadat je op deze link hebt geklikt:

On behalf of the Dutch Kingdom Amateur Radio Society, I wish you pleasant reading after you click on this link:

http://downloads.dkars.nl/DKARS%20Magazine%20201606.pdf

Wil je in plaats van een PDF te downloaden het Magazine on-line doorbladeren?
Dat kan ook, ga dan naar deze link:

Want to download the magazine browsing on-line instead of a PDF? This can also go to this link:

http://issuu.com/pj4nx/stacks/908f8b31fac742848591b9f65d971397

https://issuu.com/pj4nx/docs/dkars_magazine_201605

73 namens de DKARS
Peter de Graaf
PJ4NX en PA3CNX
Secretaris DKARS

 

Vintage Type Transmitter

Purchased this a while back and not sure what I have.

Transmitter with a pair of 807's.

Any info would be appreciated...

73 and have a great 4th...Mark

.

Mark,
The small modulator section (just two tubes?) suggests that the rig is screen modulated AM rig.

Obviously crystal controlled, it has a basic transmitter lineup much like the late 50's WRL Globe Chief 90 (which was CW only).

That rig used a pair of 807s in the final, a 6AG7 oscillator, and a 5U4-GA (or GB) rectifier.

Designed for the Novice class operator, it was rated at 90 watts CW input power (max).

Based only on that tube lineup, I estimate that your mystery transmitter is probably capable of maybe 25-35 watts AM output.
    War Story: A red line on the Globe Chief 's ammeter denoted the maximum plate current for the (then) Novice Class legal limit of 75 watts input power.

Oddly enough, many - if not most - Novice licensees religiously avoided transmitting above 75 watts for fear of a visit from the FCC.

I know for sure that one Novice licensee was that careful, and even noted the exact power reading in every single log book entry.
My memory is vague, but the WRL screen modulator kit, a bolt-on offered for the later Globe Chief Deluxe, included two tubes, one of them a 12AX7 (IIRC).

That, in addition to the low-component modulator section, prompted me to suggest in was a screen modulated AM transmitter.
Gary, K9ZMD
REM :

I'd like to know what the other tube is. 6U8 for audio preamp?

At one point I thought it might be a VR tube for the screen modulator, but it doesn't look tall enough.
Nice construction!
73 Mark K3MSB
REM :

Mark,
OK, I did a little browsing and learned that the bolt-on screen modulator I mentioned earlier is the
WRL SM-90, which used two tubes: a 12AX7 speech amplifier and a 12AU7 driver and screen modulator.
And yes, the HB construction of your little rig is admirable.
Gary, K9ZMD
REM :

Hello,
Appears to be a pair of 807s driven by a xtal controlled 6AG7 oscillator and a 5U4(GB) rectifier, the same tube line-up as a WRL Globe Chief.
73, Sam Neal N5AF
REM :

Tubes are 6AG7...12AX7...12AU7...Rectifier tube is not connected underneath.

Pic is of other piece I have.

Pretty sharp Larry!

73 Mark K3MSB

REM :

It looks like a nice home brewed transmitter.

The meter may well be from an early Heathkit.

The capacitor looks like one from a Command set transmitter.

Back in the 50s, we made many such rigs from scrounged parts.
older ARRL Handbooks may have the schematic.

Look up WRL Globe transmitters for schematic hints as well.

Joe V31JP

REM :

The Globe Chief had a little box with two triodes which screen modulated the 807's.

It plugged into and was supported by the 8 pin octal socket.

The last stage of the modulator was essentially a series regulator for the screen grids.

Of course this cut the power in about half.

Said it previous posting, never could get it to modulate fully, received a lot of comments about low modulation level.

I still have my Globe Chief and the original assembly/operations manual is carefully in a file in my file cabinet.

I am going to sell Globe Chief, hate but running out of room.

I am 75 and things move slowly.

But this fall I am going to set up my vintage operating position, a Heathkit AT-1 and a 40 and 80 meter ARC-5 receivers.

Just wonder if I can do it again like I did when I was 15.

 I am thinking of making one of those vintage 6L6 single stage transmitters, remember the one where you hand spun the tank coil on a form of 12 nails.

So much of the past, now I am up to JT-65.

James Brock

REM :

That sure looks like knock off of a World Radio Globe Chief with a carrier controlled modulator.

The only thing that doesn't look right is the little transformer or choke in the modulator.

They originally used a carrier control modulator connected to the screen grids of the 807's.

The 807's were a very popular tube back then.

The coil output loading coil looks exactly like the Globe Chief.

BTW, haven't used it for decades but still have my original transmitter that I purchased in 1959, factory wired and cost about $89.

Using it and my Halliscratchers S-20r I made many enjoyable contacts.

Oh, forgot, the AM modulation level was always very low, just the way it was then.

W7DAU Licensed 60+ years

James Brock 

 

 

73, your Editor PA3CLQ

 

-30-

 

pa3clq@casema.nl

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