05-25-2015, 07:58 AM
Well a few days ago L76 got a the chance to meet it's little bro 7C . HRO serial # started D in 1935 and run thru mid 1938 with Z. Then they started with the consecutive # made and then the run letter. L 76 is run L (9th) and the 76'th set built and 7C is the 7th set built from run C. It gets a little bit more confusing later when the letters are the same for the pre and post 1938 sets.
Anyway 7C dates to about February 1939. Doubtful that it saw any WWII action as an intell receiver but I have read that some Brits where send over here to purchase HRO's for the govt. This would be probably later in '39 At this time the US was trying to stay neutral so the Lend-Lease program hadn't started that would start a little later. That's when the Brits got most of them and those are a bit newer using octal tubes and having more markings on the front panel. These two use the older standard based tubes.
7C is in good shape and it's not green! Did come with 1 coil 500 to1000kc. All very original and just a few minor repairs. When the previous owner got it it was missing all the tubes and shields. Fortunitly he found them, the proper shields are hard to come by these days the tubes not so much. But he stated that it didn't work.
Now for the dilemma. Should I try to power it up??? There is no hv filters in the set (power supply is separate).
Terry
Below a pic from Bletchley Park (UK) where the Hro's were used to intercept Axis coded messages.
Anyway 7C dates to about February 1939. Doubtful that it saw any WWII action as an intell receiver but I have read that some Brits where send over here to purchase HRO's for the govt. This would be probably later in '39 At this time the US was trying to stay neutral so the Lend-Lease program hadn't started that would start a little later. That's when the Brits got most of them and those are a bit newer using octal tubes and having more markings on the front panel. These two use the older standard based tubes.
7C is in good shape and it's not green! Did come with 1 coil 500 to1000kc. All very original and just a few minor repairs. When the previous owner got it it was missing all the tubes and shields. Fortunitly he found them, the proper shields are hard to come by these days the tubes not so much. But he stated that it didn't work.
Now for the dilemma. Should I try to power it up??? There is no hv filters in the set (power supply is separate).
Terry
Below a pic from Bletchley Park (UK) where the Hro's were used to intercept Axis coded messages.