[ARC5] ARC5 Digest, Vol 109, Issue 45 those 25L6s in the BC-1206-A

[Paddy Ryan]

There is a 6SS7 in something here ,probably a heavily 'improved' ARC-5 
receiver but I am interested in the reference to those two 25L6s in the 
1206-A..at first glance I assumed that 2 AF tubes meant push pull but not 
so..why 2 25L6s in parralel? what is the purpose of the two? is it just to 
keep the audio operating in the event of one failing? I have not seen this 
before? ..73 de Pat/EI7CN

-----Original Message----- 
From: arc5-request at mailman.qth.net
Sent: Wednesday, February 06, 2013 4:13 PM
To: arc5 at mailman.qth.net
Subject: ARC5 Digest, Vol 109, Issue 45

Send ARC5 mailing list submissions to
arc5 at mailman.qth.net

To subscribe or unsubscribe via the World Wide Web, visit
http://mailman.qth.net/mailman/listinfo/arc5
or, via email, send a message with subject or body 'help' to
arc5-request at mailman.qth.net

You can reach the person managing the list at
arc5-owner at mailman.qth.net

When replying, please edit your Subject line so it is more specific
than "Re: Contents of ARC5 digest..."


Today's Topics:

   1. Re: 6SS7 (Ian Wilson)
   2. 6SS7 (Robert  Eleazer)
   3. Re: 6SS7 (john rose)


----------------------------------------------------------------------

Message: 1
Date: Wed, 6 Feb 2013 07:43:11 -0800
From: Ian Wilson <ianmwilson73 at gmail.com>
To: wrcromwell at gmail.com
Cc: arc5 at mailman.qth.net
Subject: Re: [ARC5] 6SS7
Message-ID:
<CAEz8jcSUUuFWTu0JJb+g57MwyYr0mAgH6e9mLbp7FS2QLO6cnQ at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

Good catch, Bill. I would never have suspected a 0.15A heater.

73, ian K3IMW

On Wed, Feb 6, 2013 at 6:54 AM, Bill Cromwell <wrcromwell at gmail.com> wrote:

>
> I have a radio or two around here somewhere with *SS7 tubes where the
> *SK7 once lived. Heater requirements are different so don't stuff into a
> series string where 6SK7 lived. Plate dissipation is somewhat lower,
> too. For an IF amp that is probably not an issue.
>
> 73,
>
> Bill  KU8H
>
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>


------------------------------

Message: 2
Date: Wed, 6 Feb 2013 10:56:49 -0500
From: "Robert  Eleazer" <releazer at earthlink.net>
To: <arc5 at mailman.qth.net>
Subject: [ARC5] 6SS7
Message-ID: <85636E98DDEF4D3BAF8F74F95DE5D0F5 at DH26DQ31>
Content-Type: text/plain; charset="iso-8859-1"

"I have a radio or two around here somewhere with *SS7 tubes where the *SK7 
once lived. Heater requirements are different so don't stuff into a series 
string where 6SK7 lived. Plate dissipation is somewhat lower,
too. For an IF amp that is probably not an issue. 73, Bill  KU8H"

That's the really funny thing.  The 6SS7 has half the filament current of a 
6SK7, and the set uses a mix of series and parallel filament circuits.  So 
it makes a difference which one you use.

It appears the early Detrola 438's use two 6V6's in the audio output - with 
some big resistors back there.  The slightly later BC-1206-A military 
versions use a 28D7, and the later BC-1206-B uses two 25L6's.

Makes me wonder if the 438 originally was designed for 12VDC for civilian 
applications.  I wonder if that would work.  I have run my ARC R-511 on 
28VDC on both B+ and filaments, but have not heard of sets going lower than 
that.

Other than the audio section the rest of the tubes seem to be the same 
except for the anomalous 6SS7.

By the way, in case you ever wondered, 6V6's get Real Bright when you plug 
them into a circuit designed for 25L6's...

Wayne




------------------------------

Message: 3
Date: Wed, 6 Feb 2013 08:13:47 -0800
From: john rose <brokenthumb at live.com>
To: arc5 mail list <arc5 at mailman.qth.net>
Subject: Re: [ARC5] 6SS7
Message-ID: <BAY167-W14043FFA5FF2881429DB8A6DA070 at phx.gbl>
Content-Type: text/plain; charset="iso-8859-1"


The HQ129x I had many years ago had 2 (I think) in the IF. The 'Stanley 
Stanley' has more gain than the 'Stanley Kilo' along with less noise and 
about half the heater current. If all the tube heaters are in parallel, they 
are essentially interchangeable.
> From: releazer at earthlink.net
> To: arc5 at mailman.qth.net
> Date: Wed, 6 Feb 2013 09:20:54 -0500
> Subject: [ARC5] 6SS7
>
> I have been investigating my collection of five Detrola 438 receivers, 
> sometimes known as the BC-1206.  I have found I have three separate 
> varieties, and more on that later.
>
> But in the only set that works I have found a tube I have never seen or 
> heard of before, a 6SS7.  I thought at first it was a bad label, despite 
> that the marking is quite clear, but I can also seen the tube type 
> embossed in the metal, so that is indeed what it is.  It appears that the 
> other sets have a 6SK7 (2) in that spot, or else an unknown glass Ken Rad 
> tube (2).
>
> Anyone ever hear of a 6SS7?
>
> Thanks,
>
> Wayne
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html


------------------------------

_______________________________________________
ARC5 mailing list
ARC5 at mailman.qth.net
http://mailman.qth.net/mailman/listinfo/arc5


End of ARC5 Digest, Vol 109, Issue 45
*************************************