zeno wrote:

I have already decided not to worry about
keeping this thing "original", eg. will be putting in a new power plug, key
jack, and coax connector etc....

It is certainly your radio and you can do as you wish,
but I urge you to reconsider; this isn't a old Craig CB rig
or and Eico 753. This radio has historic significance.

Extensive modification is needless
and will turn your historic relic into a junkbox nothing.
You can get the rig on the air with a good signal
without drilling a single hole or chopping out anything.
It's as simple as disconnecting
one wire and adjusting one relay contact.
If you need pins to fit the power connector on the back,
send me your address and I'll send you some.
Moreover, if you do the butchery to put the filiments on
12 volts AC, you are defeating part of the engineering solution
designed to keep the rigs stable.
My rigs are original design and work great with
good power out and little or no chirp.

First- throw out ALL those "conversion" articles from
the 50s, 60s and 70s. The first ones were written by
people who knew nothing about getting these rigs going
and the rest just parroted what the first wrote.
I can't tell you how many rigs went from "war relic"
to "trash can" because of some conversion "author."
The rigs are NOT TVI machines, chirp factories,
harmonic generators or any of the other myths
you've heard. These were born out of people flailing
around blindly without any understanding of how
the rig was designed to work.

I have lots of information on how to get these going
with little work and no irreversable mods.
I'm headed to work. If anyone cares to read them,
I will post them when I get home this evening.

73 DE Dave Stinson AB5S

Thanks to everyone for the encouragement. Next step is to make the conversion
to this little power supply, then tweak that oscillator plate voltage etc. and
see if I can get it on the air. I have already decided not to worry about
keeping this thing "original", eg. will be putting in a new power plug, key
jack, and coax connector etc. I am sure I will have many more questions as I
proceed and will keep you posted with the progress and inevitable mysteries
that will need solving....

Why do you think the regulated dc on the filaments makes such a difference?
Closer to the original battery powered situation? Would that be true for any
old tube transmitter? Or because these particularly were originally designed to
run on 28 volt DC.


Bill, K6TAJ


COLIN LAMB wrote:

The ARC-5 transmitter is one of the great piece of electronics out of WWII.
As a kid, my first transmitter was an ARC-5 bought from JJ Glass of Los
Angeles for about $5.95. It was brand new and a beauty to behold. Getting
it working right will teach you everything that you need to know about
electronics (well as of 1957 anyway).

I was able to get mine to key nicely with no chirp at all. I still have a
wall full of them, they are nice to look at. You should be able to find a
schematic on the internet. I found that adjusting the oscillator plate
voltage to the individual transmitter could help solve a lot of problems and
regulated dc on the filaments does wonders, too. They will run 100 watts
without too much strain, although the power supplyis often twice the size of
the transmitter. But, they also run qrp on a much smaller supply and lower
voltage.

Have fun, Colin K7FM

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Nostalgia. When drafted into the Navy is 1943
my first job was setting up ARC-5 transmitters
and receivers in 336 SNJ (AT-6) aircraft. (among
other things) Later after the war when there wasn't
much money around, I would rewind ARC-5 receivers
and use them for ten-meter converters. In those days
tapping on the case of just about any transmitter or
receiver would produce some modulation. Except for
Collins equipment. The ARC-5 VHF transmitters were
truly awe inspiring when they arrived. 73s W6BWY

God bless you; you're just the man I'm looking for.
Do you have any idea what the MF ARC-5 transmitters
were for? These are the rare :
T-15, 500-800 KC
T-16, 800-1300 KC
T-17, 1300-2100 KC

The latest theory is that they were used in joint
maneuvers with third-world allied navies,
where were still using the 1920s-agreed navy
frequencies below 2 MC.

There so much I would love to ask you about
these sets, if you don't mind the trouble.
I'm a serious historian of the
Command Set series and gentlemen like yourself
are a treasure to find.

73 DE Dave Stinson AB5S


Spike wrote:

Nostalgia. When drafted into the Navy is 1943
my first job was setting up ARC-5 transmitters
and receivers in 336 SNJ (AT-6) aircraft. (among
other things) Later after the war when there wasn't
much money around, I would rewind ARC-5 receivers
and use them for ten-meter converters. In those days
tapping on the case of just about any transmitter or
receiver would produce some modulation. Except for
Collins equipment. The ARC-5 VHF transmitters were
truly awe inspiring when they arrived. 73s W6BWY

I have a T-16 NOS in the box. Opened only for inspection. It going to the
'E' place.



"David Stinson" wrote in message
news:bJDvd.3553$Zn6.2981@trnddc08...
God bless you; you're just the man I'm looking for.
Do you have any idea what the MF ARC-5 transmitters
were for? These are the rare :
T-15, 500-800 KC
T-16, 800-1300 KC
T-17, 1300-2100 KC

The latest theory is that they were used in joint
maneuvers with third-world allied navies,
where were still using the 1920s-agreed navy
frequencies below 2 MC.

There so much I would love to ask you about
these sets, if you don't mind the trouble.
I'm a serious historian of the
Command Set series and gentlemen like yourself
are a treasure to find.

73 DE Dave Stinson AB5S


Spike wrote:

Nostalgia. When drafted into the Navy is 1943
my first job was setting up ARC-5 transmitters
and receivers in 336 SNJ (AT-6) aircraft. (among
other things) Later after the war when there wasn't
much money around, I would rewind ARC-5 receivers
and use them for ten-meter converters. In those days
tapping on the case of just about any transmitter or
receiver would produce some modulation. Except for
Collins equipment. The ARC-5 VHF transmitters were
truly awe inspiring when they arrived. 73s W6BWY

I have a T-16 NOS in the box. Opened only for inspection. It going to the
'E' place.



"David Stinson" wrote in message
news:bJDvd.3553$Zn6.2981@trnddc08...
God bless you; you're just the man I'm looking for.
Do you have any idea what the MF ARC-5 transmitters
were for? These are the rare :
T-15, 500-800 KC
T-16, 800-1300 KC
T-17, 1300-2100 KC

The latest theory is that they were used in joint
maneuvers with third-world allied navies,
where were still using the 1920s-agreed navy
frequencies below 2 MC.

There so much I would love to ask you about
these sets, if you don't mind the trouble.
I'm a serious historian of the
Command Set series and gentlemen like yourself
are a treasure to find.

73 DE Dave Stinson AB5S


Spike wrote:

Nostalgia. When drafted into the Navy is 1943
my first job was setting up ARC-5 transmitters
and receivers in 336 SNJ (AT-6) aircraft. (among
other things) Later after the war when there wasn't
much money around, I would rewind ARC-5 receivers
and use them for ten-meter converters. In those days
tapping on the case of just about any transmitter or
receiver would produce some modulation. Except for
Collins equipment. The ARC-5 VHF transmitters were
truly awe inspiring when they arrived. 73s W6BWY

God bless you; you're just the man I'm looking for.
Do you have any idea what the MF ARC-5 transmitters
were for? These are the rare :
T-15, 500-800 KC
T-16, 800-1300 KC
T-17, 1300-2100 KC

The latest theory is that they were used in joint
maneuvers with third-world allied navies,
where were still using the 1920s-agreed navy
frequencies below 2 MC.

There so much I would love to ask you about
these sets, if you don't mind the trouble.
I'm a serious historian of the
Command Set series and gentlemen like yourself
are a treasure to find.

73 DE Dave Stinson AB5S


Spike wrote:

Nostalgia. When drafted into the Navy is 1943
my first job was setting up ARC-5 transmitters
and receivers in 336 SNJ (AT-6) aircraft. (among
other things) Later after the war when there wasn't
much money around, I would rewind ARC-5 receivers
and use them for ten-meter converters. In those days
tapping on the case of just about any transmitter or
receiver would produce some modulation. Except for
Collins equipment. The ARC-5 VHF transmitters were
truly awe inspiring when they arrived. 73s W6BWY

In article , zeno writes:

Someone gave me an old ARC 5 (7-9.1) transmitter found at the county
dump. I would like to see if I can get it going on 40 meter CW.

First question is: What condition is it in?

If it's in original unmodified condition, or close to it, please don't hack it
up. Unmodified ARC-5s *used to be* all over the place for low prices, and were
often subjected to all sorts of modifications. Some mods were pretty good, most
really weren't. IMHO, one that's survived this long in unmodified shape
deserves to be preserved. If you don't want to keep it historically accurate,
sell it to someone who does. There are plenty of hacked-up ones around to
experiment with.

OTOH, if it's been through the mods already (power socket changed, lots of
extra holes, coils rewound, paint largely gone, etc.) it might be OK to mod it
or use it as a parts source.

I have
found some information online, namely a schematic and an article for
"converting to Amateur use". I realize this is a crap shoot, but I
think it would be fun trying. I am trying to verify the wiring
according to this old schematic knowing that so many units have been
hacked into over the years. I have put together a power supply along
the lines of the reprinted "converting" article available at the ARRL
website.

What does that conversion article show?

There was an article in the ARRL Handbooks for years that involved building an
external crystal oscillator in a minibox, using a 6AG7. Most of that article
was pretty good because it didn't hack up the ARC-5 too much (but it did
recommend destroying the power socket, unfortunately).

The Xtal in this unit is 8870 KC. Is this OK?

Not for ham operation!

How does this
Xtal function in this otherwise VFO unit, and what determines the
frequency that was chosen for this xtal?

It allowed the dial to be checked against one known point, using the 1629
magic-eye tube. This was a simple check that could be done in the plane to be
sure that things weren't way off. ARC-5 transmitters (when used in small
planes) were usually meant to be adjusted on the ground by a technician, who
would then lock all the settings and the pilot would simply choose which
transmitter to use.

Other information or sources
of information would be welcome.

KG7BZ website, if it's still operational


Anyone else have any luck with these
things? Any recommendations?

They are an excellent example of 1930s radio engineering at its very best. They
did the job with a maximum of efficiency and a minimum of size, weight,
complexity and cost. The receivers are even better.

73 de Jim, N2EY

btw, about 12 years or so ago, a local ham showed me an intact BC-459. A little
dusty but completely untouched. He found it on someone's trash, wanted to know
if it was worth carting to the upcoming hamfest and if so, how much to ask. I
said $25 and he thought I was nuts. It was the first thing he sold.

N2EY wrote:

In article , zeno writes:

Someone gave me an old ARC 5 (7-9.1) transmitter found at the county
dump. I would like to see if I can get it going on 40 meter CW.

First question is: What condition is it in?



The one has already been modified, the other is relatively unmodified, but missing
the bottom and the top case.





What does that conversion article show?

There was an article in the ARRL Handbooks for years that involved building an
external crystal oscillator in a minibox, using a 6AG7. Most of that article
was pretty good because it didn't hack up the ARC-5 too much (but it did
recommend destroying the power socket, unfortunately).


Yes, that is the article. I also have a power supply that works and has an octal
male plug as described in that article. I would have to add an octal female socket
on the back of the unmodified unit to receive this power supply plug. If I were to
attempt to put the modified unit back together I would need way more information
than I have at this point. For example the unmodified unit has an RF choke next to
the large vertical coil in from of the 1625s, on the modified unit, it looks like
it never had this rf choke installed. There are little wiring differences like
this in these two units which I do not understand. The vertical coil in the
unmodified unit has the red number 9295 printing on its edge, the modified unit
has the number 7250 on it. I do not know what this number means (?).

What (where would I get) information would I need to rebuild a totally modified
unit, to make it into some kind of an operating transmitter?



The Xtal in this unit is 8870 KC. Is this OK?

Not for ham operation!


The way I understand it, this is just for calibration of the VFO, so it is OK.




My original intention was to recreate a 50's style conversion of one of these
transmitters, however, I am not wondering if there is not a better way to go.

Bill k6TAJ

zeno wrote:
The one has already been modified, the other is relatively unmodified, but missing
the bottom and the top case.

Send me your mailing address.
I'll dig out a bottom and a top for your rig.

Concerning the power supply in the ARRL book-
It isn't the best design for the rig.
I'm putting together a couple of posts about all this
and will have them up shortly.

73 Dave S.