PN1-xTransmitter/Receiver

Type: Portable Transmitter-Receiver
Variants: From nameplate data, the PN1 comes in  -A and -B versions. The difference between the variants are not known at this time.
Modes: CW and AM
Frequency Range: 3000 to 6000 KHz.
Frequency control : 3 crystal controlled frequencies
Sample frequencies actually used: 3480, 3600, 4172 and 4850 KHz
Transmitter Power Output: 300 mw (estimate)
Tube Lineup: 2 x 1P5, 1A7, 1G4, 1H5, 1Q5, 1J6, 1H4, 1J6 and 1F5
Vintage: Believed to be 1940
Marconi type no: 118-980
Diagram: 141-206 (also see #99380 on the chassis of the PN1-A)

Dimensions: 15 1/2 " tall      15 1/2" wide           9 1/4" deep
Weight: 11.15 KG (24.6 lbs)  with phones, mike but without battery.
Telescoping antenna: 14 inches collapsed. 72 inches extended.
Power: Light duty 'B' battery 180 VDC and 3 volt 'A' battery - 6 to 8 hours
             Heavy duty 'B' battery 180 VDC and 3 volt 'A' battery - 60 to 80 hours.
             If the 'A' battery drops below 2 volts or the 'B' below 120 volts,
             then a battery replacement is required.
             Also requires a 3 volt 'C' battery.

EXTERIOR VIEWS

pni_front_panel1.jpg
With accessories cover in place
pni_front_panel2.jpg
Battery and accessories compartment
pni_front_panel3.jpg
Right side
pni_frontpanel4.jpg
Left side : showing antenna connection post. It would appear that a telescoping antenna may have been an option as attested by the Sparker's hand drawn sketch elsewhere in this document. The holes are 2 inches in diameter.
pni_covers_on.jpg
Front view with cover in place.
pni_rear.jpg
Rear view
pni_nameplate.jpg
Nameplate
All PN1-B photos in this table by Moe Fretz

 

 CASE, HEADPHONES and MIC

pni_interior1.jpg
Note how the RF makes it from the chassis to the antenna connection terminal at the left  via the red  insulated wire and the thick conductor. 
pni_interior2.jpg
With chassis pulled. 
pni_headphones.jpg
Headphones and microphone. 
All PN1-B photos in this table by Moe Fretz

CHASSIS VIEWS

pni_chassis1.jpg
pni_chassis2.jpg
The three crystals plug into sockets which are in the upper left corner of the photo and covered with a metal strip. In the centre foreground is the holder for the 4.5 volt "C" battery. The brown zip cord connects to the battery.
pni_chassis3.jpg
pni_chassis4.jpg
pni_chassis5.jpg
All PN1-B photos in this table by Moe Fretz

 PN1-A PHOTOS


pn1a_radio_gray.jpg
This PN1-A appears gray in colour. Mounted on the storage clips is the telescoping antenna which could be extended to 72 inches. 
pn1a_controls.jpg
Closer view of the controls. 
pn1a_nameplate.jpg
PN1-A nameplate
pn1a_top_view_internal.jpg
The 'C' battery in this set managed to survive for decades after it was installed. 
pn1a_bottom_view_of_internals.jpg
Chassis underside view of the PN1-A.
pn1a_crystals.jpg
With two crystals in place.
All PN1-A photos in this table by Jason Racine
PN1 TUNING PROCEDURE

1) Remove set from case.
2) Place crystals in desired channels.
3) Place 'C' battery in position and plug in.
4) Attach power cable to 'A' and 'B' batteries.
5) Plug power lead into left hand position under set.
6) Plug earphones into right hand position under set.
7) With switch set to 'Receive', turn on power switch.
8) Turn centre dial to 'B' volts . It should read 180 volts on the meter above.
9) Turn same switch to 'Trans Fil' . Now turn set to 'Send'. Turn rheostat so
     that meter above reads 2.15 volts
10) Switch to 'Trans Tune' and check crystal oscillation as follows:

With set 'on' locate screw for the proper channel on right side of set. Turn this screw until needle reads maximum and then drops off suddenly. Bring needle up to maximum again and then back it off slightly on the slow side of slope. The crystal is now oscillating properly.
11) Turn set off.
12) Disconnect leads and replace set in case.
13) Connect leads again and plug in antenna and speaker. Connect aerial at left of set.
14) Turn to 'Send' and with 'Coupling' at low side, tune 'Transmit' dial for a dip in the needle. Turn 'Coupling' up, tuning for a dip at each notch. When this dip. is located between 25 and 35 milliamps the set is tuned to resonance with the proper output reading.
NOTES ABOUT THE PN1 FROM A SPARKER'S TRAINING NOTES


pni_sketch.jpg
This hand drawn sketch of the PN1 came from a Sparker's training notebook.

 
CONTROLS
1. Off/On Switch  9. Coupling 
2. Volume control 10. Transmitter tuning
3. BFO off switch 11. Locking device
4. Receiver Tuning 12. Key jack
5. Locking device 13. Xtal channel switch 
6. Aerial Terminal 14. Send-Rcv switch
7. Filament rheostat 15. Power connection
8. Three position meter switch. Monitors transmitter filaments, 'B' voltage and transmitter tuning.  16. Audio connection
The send receive relay is operated by the Send/Rcv switch or the press to talk button on the microphone. This relay switches the aerial from the receiver to the transmitter, the filament supply from the receiver to the transmitter.
CASE COLOURS
Beside being painted in olive drab as above, the PN-1 was also painted in blue-green for those units supplied to the RCAF.
pn1_green_01.jpg
pn1_green_02.jpg
PN-1 photos in this table by  Garey Valcourt
 


Credits and Contributors:

1) Moe Fretz <tubetester(at)gmail.com> Collection and Preservation Of Canadian Tube Radios, Communication Equipment,  Vintage Ham gear and Military Radios.
2) Jason Racine <thebuckhunter(at)cogeco.ca>
3) Bruce MacMillan <bruce_macmillan(at)telus.net>
4) Garey Valcourt

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Mar 1/10