Hallicrafters S27 - UK Vintage Radio Repair and Restoration Discussion Forum

Peter73 · 11th Oct 2018, 7:34 pm

I have recently acquired a rather nice Hallicrafters S27 receiver in what appears to a fairly original unmolested condition.
I would be very interested in discovering the war time history of the set, I have attached some photo's of the set and the ID plates.
Also does any member know of a UK company that could reproduce the celluloid tuning dials as the bandspread dial is split.
Radio Daze in the USA can supply a new S meter dial but not the tuning dials at the moment.
Peter.

G6Tanuki · 11th Oct 2018, 8:00 pm

Nice!

I wonder what the "AM Modifications" were? These were used during WWII as part of the effort to identify and locate the german 'Knickebein' navigation-beams, as well as trying to listen for radio-control signals being sent to early V2 rockets [the 'production' V2 didn't use radio-control and depended on inertial navigation].

I can understand the Air Ministry doing modifications if they were going to fly these in the like of Ansons. [The 1970s BBC series 'The Secret War' has a short clip of William Woolard(sp?) in an Anson with a S27]

The S27 I've got here has a "Pye" type coax-socket fitted to the rear panel and a screened-on front-panel identification that it's so modified.

"Modified for coaxial

?"

It's interesting too that round the 'Pye' coax socket on mine appear to be three small holes in a triangular layout - along with a hint of a circular 'shadow' on the chassis-plating, as if there was perhaps an earlier style of coax socket fitted before the Pye connector>??

Peter73 · 11th Oct 2018, 9:17 pm

I am just reading The Secret War by Brian Johnson which mentions the S27 in various chapters.
The aerial connectors on mine appear to be very basic but original.
Is there any way of dating these sets, I am assuming mine is around 1940/41.

turretslug · 11th Oct 2018, 9:24 pm

I'm sure I recall a three-hole coax fitting on some versions of the CR100, though I've no idea of its designation.

Did the receivers have provision for 240VAC operation as standard, or just US market mains- perhaps the mod was a UK-suited mains transformer. Or (clutching for those straws) a wider IF bandwidth for supersonic modulation, monitored by something wider-band than the human ear?

dave walsh · 11th Oct 2018, 10:41 pm

I've got one of these. With a top f of 143 Megs I think they sometimes got modified for 2 Metres!

Dave

G6Tanuki · 12th Oct 2018, 8:55 am

Quote:

Originally Posted by turretslug

I'm sure I recall a three-hole coax fitting on some versions of the CR100, though I've no idea of its designation.

Did the receivers have provision for 240VAC operation as standard, or just US market mains- perhaps the mod was a UK-suited mains transformer. Or (clutching for those straws) a wider IF bandwidth for supersonic modulation, monitored by something wider-band than the human ear?

Mine has a non-standard [rather larger] mains transformer fitted: it _looks_ to be rather old (cloth-covered leadout wires...) so I imagine it could have been fitted early in the radio's life. Equally, it could have been an 'old' surplus part that was fitted later to replace a burned-out original.

The 'wide' bandwidth positiongives 50KHz bandwidth, so there wouldn't have been much need to modify it to receive above-human-hearing modulation. I'd have expected this to be done though ny fitting a separate 'IF-out' socket so whatever Blumlein or Watson-Watt wanted could be coupled up as an external unit.

Interestingly, a few photos down here:

http://www.alternatewars.com/Bomb_Lo...Bomb_Guide.htm

shows what some claim is a S27 and others a S36 (at one time during WWII on the Hallicrafters production-line the front plates were seemingly interchanged depending on what they had and how urgent the order was...) Apparently it's being used to set up the radar-altimeter that triggered the bomb at the required height.

M0FYA Andy · 12th Oct 2018, 9:21 am

Interestingly the Stores Reference 110D/21 is for the Canadian Air Ministry, the British Air Ministry number would be in Section 10D.

Andy

geeoboeh2s · 15th Oct 2018, 2:39 pm

Andy,

I thought that section 110 referred to items not made in this country or to a UK specification
Valves area typical example. CV509 (6V6G) is listed as being manufactured by STC (UK) and RCA (USA) and has two Air Ministry numbers, 10E/349 and 110E/90. The former meeting an MOS specification and the latter to a JAN specification.
Interestingly CV510 (6V6) is to a JAN specification but is listed with both a 10E and 110E number.

All a bit confusing but then it was wartime.

Chris

11th Oct 2018, 7:34 pm	#1
Peter73 Triode Join Date: Dec 2017 Location: Leigh-on-Sea, Essex, UK. Posts: 11	Hallicrafters S27 I have recently acquired a rather nice Hallicrafters S27 receiver in what appears to a fairly original unmolested condition. I would be very interested in discovering the war time history of the set, I have attached some photo's of the set and the ID plates. Also does any member know of a UK company that could reproduce the celluloid tuning dials as the bandspread dial is split. Radio Daze in the USA can supply a new S meter dial but not the tuning dials at the moment. Peter. Attached Thumbnails

11th Oct 2018, 8:00 pm	#2
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,996	Re: Hallicrafters S27 Nice! I wonder what the "AM Modifications" were? These were used during WWII as part of the effort to identify and locate the german 'Knickebein' navigation-beams, as well as trying to listen for radio-control signals being sent to early V2 rockets [the 'production' V2 didn't use radio-control and depended on inertial navigation]. I can understand the Air Ministry doing modifications if they were going to fly these in the like of Ansons. [The 1970s BBC series 'The Secret War' has a short clip of William Woolard(sp?) in an Anson with a S27] The S27 I've got here has a "Pye" type coax-socket fitted to the rear panel and a screened-on front-panel identification that it's so modified. "Modified for coaxial ?" It's interesting too that round the 'Pye' coax socket on mine appear to be three small holes in a triangular layout - along with a hint of a circular 'shadow' on the chassis-plating, as if there was perhaps an earlier style of coax socket fitted before the Pye connector>?? Attached Thumbnails

11th Oct 2018, 9:17 pm	#3
Peter73 Triode Join Date: Dec 2017 Location: Leigh-on-Sea, Essex, UK. Posts: 11	Re: Hallicrafters S27 I am just reading The Secret War by Brian Johnson which mentions the S27 in various chapters. The aerial connectors on mine appear to be very basic but original. Is there any way of dating these sets, I am assuming mine is around 1940/41. Attached Thumbnails

11th Oct 2018, 9:24 pm	#4
turretslug Dekatron Join Date: Nov 2011 Location: Surrey, UK. Posts: 4,394	Re: Hallicrafters S27 I'm sure I recall a three-hole coax fitting on some versions of the CR100, though I've no idea of its designation. Did the receivers have provision for 240VAC operation as standard, or just US market mains- perhaps the mod was a UK-suited mains transformer. Or (clutching for those straws) a wider IF bandwidth for supersonic modulation, monitored by something wider-band than the human ear?

11th Oct 2018, 10:41 pm	#5
dave walsh Dekatron Join Date: Jan 2006 Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex. Posts: 5,817	Re: Hallicrafters S27 I've got one of these. With a top f of 143 Megs I think they sometimes got modified for 2 Metres! Dave

12th Oct 2018, 9:21 am	#7
M0FYA Andy Nonode Join Date: May 2007 Location: Preston, Lancashire, UK. Posts: 2,511	Re: Hallicrafters S27 Interestingly the Stores Reference 110D/21 is for the Canadian Air Ministry, the British Air Ministry number would be in Section 10D. Andy

15th Oct 2018, 2:39 pm	#8
geeoboeh2s Rest in Peace Join Date: Mar 2010 Location: Berkshire, UK. Posts: 72	Re: Hallicrafters S27 Andy, I thought that section 110 referred to items not made in this country or to a UK specification Valves area typical example. CV509 (6V6G) is listed as being manufactured by STC (UK) and RCA (USA) and has two Air Ministry numbers, 10E/349 and 110E/90. The former meeting an MOS specification and the latter to a JAN specification. Interestingly CV510 (6V6) is to a JAN specification but is listed with both a 10E and 110E number. All a bit confusing but then it was wartime. Chris