Litzendraht wrote:
I have the book on the SCR 522, but no way to scan and forward
schematics.

Do you have a specific question about the receiver? I am familiar with
the equipment. I used the BC 624 and 625 almost 45 years ago as my two
meter AM station.

John

Hello ,thanks for your answer.I have no precise question,I have bought
one on ebay ,it is electronically complete ,and without problem (maybe
the chemical condensers to change),and mecanically the mecanism of
tuning has been removed ,but not the variable condensers and coils.
I plan to do use it to do radio-astronomy ,yes it may seem a fool
project ,but one part of my hobby besides radio-amateur is
radio-astronomy ,and I wanted to use a receiver like they were at
the beginning of radio-astronomy on vhf just to know what was received
from the sun at that time .This is why I'd like to have the schematic
with values of resistors ,condensers etc,and the
connectors ,so I can use it and repair it .
Thanks very much,best 73 alain f1gqb

nierveze wrote:
Litzendraht wrote:

I have the book on the SCR 522, but no way to scan and forward
schematics.

Do you have a specific question about the receiver? I am familiar with
the equipment. I used the BC 624 and 625 almost 45 years ago as my two
meter AM station.

John

Hello ,thanks for your answer.I have no precise question,I have bought
one on ebay ,it is electronically complete ,and without problem (maybe
the chemical condensers to change),and mecanically the mecanism of
tuning has been removed ,but not the variable condensers and coils.
I plan to do use it to do radio-astronomy ,yes it may seem a fool
project ,but one part of my hobby besides radio-amateur is
radio-astronomy ,and I wanted to use a receiver like they were at
the beginning of radio-astronomy on vhf just to know what was received
from the sun at that time .This is why I'd like to have the schematic
with values of resistors ,condensers etc,and the
connectors ,so I can use it and repair it .
Thanks very much,best 73 alain f1gqb

G'Day Alain

Ah memories - I used an SCR522 Rx & Tx on 2 metres way way back. They
were a great piece of gear and used by lots of hams.

Before you apply power to the receiver (or transmitter) check out the
..006mf mica HT bypass capacitors. Some of the sets used Micamold
capacitors which are dark brown in colour and are in fact paper not
mica. They used to break down with monotonous regularity.

Best to replace the lot (15 or so)in the receiver (and Tx). Some
SCR522's had good mica capacitors and if I remember they were light
brown in colour.

There were a couple of versions of the receiver that I know of. One
version had a squelch relay whilst the other version had electronic squelch.

I do have a manual but to copy the circuit it would be in 3 pieces and I
dont know how the small print would come out.Also have the wiring diagram.

There is a relative simple modification to make the RX tunable and not
crystal controled

You should be able to get a circuit locally if you hunt around, if not
let me know and will try sending you a copy.

73
Lionel L Sharp, VK4NS

Lionel Sharp wrote:
Ah memories - I used an SCR522 Rx & Tx on 2 metres way way back. They
were a great piece of gear and used by lots of hams.

Before you apply power to the receiver (or transmitter) check out the
.006mf mica HT bypass capacitors. Some of the sets used Micamold
capacitors which are dark brown in colour and are in fact paper not
mica. They used to break down with monotonous regularity.

Best to replace the lot (15 or so)in the receiver (and Tx). Some
SCR522's had good mica capacitors and if I remember they were light
brown in colour.

There were a couple of versions of the receiver that I know of. One
version had a squelch relay whilst the other version had electronic squelch.

I do have a manual but to copy the circuit it would be in 3 pieces and I
dont know how the small print would come out.Also have the wiring diagram.

There is a relative simple modification to make the RX tunable and not
crystal controled

You should be able to get a circuit locally if you hunt around, if not
let me know and will try sending you a copy.



Lionel,

Why don't we create an SCR 522 fan club? I eventually replaced the
832 PA with an 829B and ran about 70 watts, modulated with a pair of
1625's on two metres AM. Golly, those were my "wonder years". I was
still a kid in high school. I still have some 522 stuff about, but no
complete units. I do recall that all the equipment tags have the RAF
insignia.

John

Litzendraht wrote:
Lionel Sharp wrote:

Ah memories - I used an SCR522 Rx & Tx on 2 metres way way back. They
were a great piece of gear and used by lots of hams.

Before you apply power to the receiver (or transmitter) check out the
.006mf mica HT bypass capacitors. Some of the sets used Micamold
capacitors which are dark brown in colour and are in fact paper not
mica. They used to break down with monotonous regularity.

Best to replace the lot (15 or so)in the receiver (and Tx). Some
SCR522's had good mica capacitors and if I remember they were light
brown in colour.

There were a couple of versions of the receiver that I know of. One
version had a squelch relay whilst the other version had electronic squelch.

I do have a manual but to copy the circuit it would be in 3 pieces and I
dont know how the small print would come out.Also have the wiring diagram.

There is a relative simple modification to make the RX tunable and not
crystal controled

You should be able to get a circuit locally if you hunt around, if not
let me know and will try sending you a copy.




Lionel,

Why don't we create an SCR 522 fan club? I eventually replaced the
832 PA with an 829B and ran about 70 watts, modulated with a pair of
1625's on two metres AM. Golly, those were my "wonder years". I was
still a kid in high school. I still have some 522 stuff about, but no
complete units. I do recall that all the equipment tags have the RAF
insignia.

John

G'Day John
I am sure that many of those who used the SCR522 in the past have passed
on. When I used my SCR522 on 2 metres there was no TV and consequently
no TVI. I think that TV changed all that. Even had one that was
converted to 6 metres (the TX not RX).

There was a rather large mains power supply, the RA62 produced in the
USA for the military.

The RAAF (Royal Australian Air Force) also had mains power supply made
under contract and they are heeeavy.

The RAF and RAAF designations was the TR5043.

I believe it was descended from the RAF TR1143 VHF set which was used
very successfully in the early days of WW2 for fighter control. When the
Americans saw the successful use of VHF they took a TR1143 back to the
USA and "Copied" it and produced it as the SCR522.

Only ever saw one TR1143 in a surplus shop. I think that the TR1143
would be very rare nowadays.

Someone will correct me if I am wrong about this.

73
Lionel L Sharp, VK4NS

Lionel Sharp wrote:

I believe it was descended from the RAF TR1143 VHF set which was used
very successfully in the early days of WW2 for fighter control. When the
Americans saw the successful use of VHF they took a TR1143 back to the
USA and "Copied" it and produced it as the SCR522.

You make it sound like we (the US) were doing something evil, by lending
you our manufacturing capability, and helping you with the war effort.

-Chuck

Chuck Harris wrote:
Lionel Sharp wrote:

I believe it was descended from the RAF TR1143 VHF set which was used
very successfully in the early days of WW2 for fighter control. When
the Americans saw the successful use of VHF they took a TR1143 back to
the USA and "Copied" it and produced it as the SCR522.


You make it sound like we (the US) were doing something evil, by lending
you our manufacturing capability, and helping you with the war effort.

-Chuck
G'day Chuck
No that was not the intention. Perhaps you can suggest another word that
is more to your liking
Lionel L Sharp, VK4NS

Chuck Harris wrote:
You make it sound like we (the US) were doing something evil, by lending
you our manufacturing capability, and helping you with the war effort.


Chuck,
I think it might have been more a case of "immitation is the best
form of flattery". I wasn't old enough to remember, but us Yanks were
probably using all HF radio in our fighters and bombers. But once we
got involved in the war effort, the success of the RAF and others with
VHF radio must have told us that we needed similiar equipment. We could
have certainly started from ground zero with our own designs, but
reliable aircraft communications was a vital factor at the time, and
VHF, being still a new form of transmission in those days, would have
taken months and months on the drawing boards and lab and field testing
to come up with a viable, operational unit.

I can see where it could have been quite desireable to take a known
working design, put our Yankee spin on it and get it into production.
We and the Allies had a big job ahead of us over there and time was of
essence. And yes,we were lending and loaning supplies, equipment,
manufacturing, (and fighting men as well), as a part of a team effort
to resolve a terrific world threat.

John

Litzendraht wrote:
Chuck Harris wrote:
You make it sound like we (the US) were doing something evil, by lending
you our manufacturing capability, and helping you with the war effort.


Chuck,
I think it might have been more a case of "immitation is the best
form of flattery". I wasn't old enough to remember, but us Yanks were
probably using all HF radio in our fighters and bombers. But once we
got involved in the war effort, the success of the RAF and others with
VHF radio must have told us that we needed similiar equipment. We could
have certainly started from ground zero with our own designs, but
reliable aircraft communications was a vital factor at the time, and
VHF, being still a new form of transmission in those days, would have
taken months and months on the drawing boards and lab and field testing
to come up with a viable, operational unit.

I can see where it could have been quite desireable to take a known
working design, put our Yankee spin on it and get it into production.
We and the Allies had a big job ahead of us over there and time was of
essence. And yes,we were lending and loaning supplies, equipment,
manufacturing, (and fighting men as well), as a part of a team effort
to resolve a terrific world threat.

John

Hi John,

Everything I read says the SCR-522 was a redesign of the British TR-1123,
that was done to make it possible to mass produce it with US tooling.

Certainly the US used the TR-1123 design as a quick way of getting a working
VHF design into the war as quickly as possible. It was several years before
the much more capable ARC-1 came out.

My only objection was the way the OP stated that it was copy. It had the
familiar taste of US bashing. If I read the OP's intentions incorrectly,
and it sounds like I probably did, I am sorry.

-Chuck

nierveze wrote:


I plan to do use it to do radio-astronomy ,yes it may seem a fool
project ,but one part of my hobby besides radio-amateur is
radio-astronomy ,and I wanted to use a receiver like they were at
the beginning of radio-astronomy on vhf just to know what was received
from the sun at that time .This is why I'd like to have the schematic
with values of resistors ,condensers etc,and the
connectors ,so I can use it and repair it .
Thanks very much,best 73 alain f1gqb

Good luck with the project. I also used a 522 on 2 meters. As I recall,
they were OK in their day, but pretty insensitive by today's standards.
On the other hand, the sun is a pretty powerful transmitter! ;-)

Have you tried copying Jupiter? It's around 21 MHz; nice web site about
it. Do a web search for "Project Jove".

73,
Carter K8VT

nierveze wrote:
I plan to do use it to do radio-astronomy ,yes it may seem a fool
project ,but one part of my hobby besides radio-amateur is
radio-astronomy ,and I wanted to use a receiver like they were at
the beginning of radio-astronomy on vhf just to know what was received
from the sun at that time .This is why I'd like to have the schematic
with values of resistors ,condensers etc,and the
connectors ,so I can use it and repair it .
Thanks very much,best 73 alain f1gqb



Alain,
You might ask some of the older members of your local radio amateur
community for information and drawings of the 522. It was a very
popular set amongst hams in the post War years.

I am surprised that you will be attempting radio-astronomy work with
the BC 624. As someone mentioned, it is not a very sensitive receiver.
Most amateurs that used it began by rebuilding the front end for lower
noise and higher gain. One chap mentioned substituting 6AG5 tubes for
the 9003's. I used 6AK5's. It is a 4 channel crystal controlled unit
and perhaps for your purpose, just a few channels may be
acceptable.There are some simple changes that will allow it to be
continuously tunable from 100 to 156 Mhz without having to use quartz
crystals.

I'm sorry that I do not have ability to scan and forward information.

It might be of interest, when I was in the military, one of our search
radars operated in the "S" band (around 3000 Mhz), and I found if I
raised the antenna elevation and aimed towards the sun there was a most
dramatic increase in receiver noise.

Good luck with your project.
John