wavemeter type 1649 - UK Vintage Radio Repair and Restoration Discussion Forum

ekcopyephilips · 6th Apr 2007, 9:50 pm

Hi everyone

I have the following piece of equipment, and i wonder if anyone could tell me anymore about it.

Ita a wavemeter type W1649 made by Salford Electrical Instruments Ltd. Lookes like the main bit was made late 1944. A power supply has been added, the date on the caps in there is 1952.

I gather the RAF used to use them, but what for ?

Mike Burton

Alf Fisher · 6th Apr 2007, 10:43 pm

Hi Mike,
Wavemeters were used by the RAF and others to measure frequency- well wavelength in metres was actually used in those days. Measurements were made using a variety of principles such as tuned circuits/cavities, heterodyne and those using lecher lines and were often made as a piece of test gear to accompany a specific piece of equipment. They had a calibration graph that enabled the dial reading to be translated into wavelength or sometimes the dial was marked directly. There were ones for HF radio and there were ones for radar equipments. Wavemeters tended to operate over a limited band so an operator could be sure that his equipment was operating and also operating on the right frequency. Some had magic eye indicators to detect resonance and some used meters. Sometimes the output was a pair of phones so you could listen for zero beat frequency whilst tuning. The most common wavemeters around are probably the Class D wavemeter and the BC221.
It looks like the dial on your unit is directly calibrated but I can't make out the details on the photo.
Hope this helps.
Alf

GMB · 7th Apr 2007, 9:57 am

My only information on it is that it covers 140-250Mhz. Can you confirm that this is correct?

ekcopyephilips · 10th Apr 2007, 10:39 pm

Frequency Range :

Wavemeter :155 - 255 Mhz
Sig Gen :140 - 240 Mhz

6th Apr 2007, 9:50 pm	#1
ekcopyephilips Hexode Join Date: Dec 2006 Location: Norwich, Norfolk, UK. Posts: 440	wavemeter type 1649 Hi everyone I have the following piece of equipment, and i wonder if anyone could tell me anymore about it. Ita a wavemeter type W1649 made by Salford Electrical Instruments Ltd. Lookes like the main bit was made late 1944. A power supply has been added, the date on the caps in there is 1952. I gather the RAF used to use them, but what for ? Mike Burton Attached Thumbnails

6th Apr 2007, 10:43 pm	#2
Alf Fisher Hexode Join Date: Sep 2005 Location: Potton, Bedfordshire, UK. Posts: 293	Re: wavemeter type 1649 Hi Mike, Wavemeters were used by the RAF and others to measure frequency- well wavelength in metres was actually used in those days. Measurements were made using a variety of principles such as tuned circuits/cavities, heterodyne and those using lecher lines and were often made as a piece of test gear to accompany a specific piece of equipment. They had a calibration graph that enabled the dial reading to be translated into wavelength or sometimes the dial was marked directly. There were ones for HF radio and there were ones for radar equipments. Wavemeters tended to operate over a limited band so an operator could be sure that his equipment was operating and also operating on the right frequency. Some had magic eye indicators to detect resonance and some used meters. Sometimes the output was a pair of phones so you could listen for zero beat frequency whilst tuning. The most common wavemeters around are probably the Class D wavemeter and the BC221. It looks like the dial on your unit is directly calibrated but I can't make out the details on the photo. Hope this helps. Alf

7th Apr 2007, 9:57 am	#3
GMB Dekatron Join Date: Aug 2003 Location: near Reading (and sometimes Torquay) Posts: 3,100	Re: wavemeter type 1649 My only information on it is that it covers 140-250Mhz. Can you confirm that this is correct?

10th Apr 2007, 10:39 pm	#4
ekcopyephilips Hexode Join Date: Dec 2006 Location: Norwich, Norfolk, UK. Posts: 440	Re: wavemeter type 1649 Frequency Range : Wavemeter :155 - 255 Mhz Sig Gen :140 - 240 Mhz