I grew up reading the ARRL Handbook from the 50's-60's and the Radio Handbook by Bill Orr, W6SAI of the same vintage. They're on fleebay and might be found in larger libraries, although one near me seems to have purged the "old" books. Maybe the RSGB published similar stuff back then as well.

There are also some Rider's publications regarding repair techniques and schematics. Some may be on the internet.

--
73 de Mike, W1NR

THAT was the equation. EXISTENCE!... SURVIVAL... must cancel out... programming!

- Ruk -

I appreciate this may not be the most appropriate forum for this question but as someone who grew up with semiconductors yet has a passion for radios that glow in the dark, what's the best way for someone like me to learn tube electronics without killing myself?

I've joined the AWA and they run some education sessions, but being in the UK it's a bit unrealistic for me to attend class in New York.? I did ask about distance learning, but they have no recordings and no immediate plans to stream the classes.

I bought KJ7UMs book 'Hollow State Design' however I feel there are some basic electronic principles I'm missing that I need to get to grips with as part of my journey.

Any thoughts on buying the old Heathkit EK1/EK2 materials working through those, and recreating the projects as an introduction? Or is there a better way?

73

Martin
m0hkg

On Fri, Mar 15, 2024 at 12:40 PM, Ralph Mowery wrote:

Unless otherwise stated in a manual the tubes are left in place.? Other than the heater and sometimes another element , the tube elements are like open circuits and will not make any difference.? This is unlike solid state electronics where the semiconductors can conduct and will often have different resistance depending on the voltage of the meter.

Oh ok.? Not what I expected.? After looking at the socket pins underneath the chassis, I can see it'll be difficult to access some of the pins from the underside for measurement as switch shafts etc. are in the way.? I then assumed that the tests would be done with tubes removed to be tested right in the tube sockets from under the cabinet.? I know I need to stop assuming anything as I'm usually wrong.
Thanks for the info Ralph.??

Just started going through my Drake equipment etc. to do basic "health checks".? Starting with the R4B,
to do the "resistance tests", etc. in the manual, it's not mentioned if the tubes should be removed for accurate?
readings or to leave them in place.? I assume that no mention means to leave them??? I'm referring to the resistance numbers expected listed in the manual.
Peter
VE9KX

Robin K4IDC <RobinK4IDC@...> added the photo album TR-7 Station Liquidation N4TK : I'm helping my friend Butch Smith N4TK liquidate his TR-7 station and other ham radio items. I've put photos of the Drake gear in this folder. Additionally, there is a WH-7 watt/SWR meter in the lot; photo to be added soon. Full disclosure: the TR-7 has an issue with the BFO. We are sending it for repair and will not sell any of the station components until that repair is complete. Preference at that time will be for buyers who want the entire station. Equipment is located near Nashville, TN.

---

The following photos have been uploaded to the TR-7 Station Liquidation N4TK photo album of the [email protected] group.

• IMG_20240313_164204840.jpg
• IMG_20240313_164214487.jpg
• IMG_20240313_164228121.jpg
• IMG_20240313_164236166.jpg
• IMG_20240313_164240558_HDR.jpg
• IMG_20240313_164322583.jpg
• IMG_20240313_164332075.jpg
• IMG_20240313_164444579_HDR.jpg
• IMG_20240313_164459707.jpg
• IMG_20240313_164719800.jpg
• IMG_20240313_164733623.jpg
• IMG_20240313_164811310.jpg
• IMG_20240313_165045072.jpg

By: Robin K4IDC <RobinK4IDC@...>

I have a fair copy of the schematic, but I am OCD, and want a original copy of the full manual. I believe the copy of the board layouts should be better at least.? Just my OCD jumping up. I have original manuals for all other Drake items I have, the RV-75 is the only one missing.

73? Bob

Greetings.

I thought I would give an update on my progress.

I had to completely disassemble the remote antenna switch, including the motor.? It was completely seized up with rust, gunk and who knows what else.? After cleaning and reassembly it works fine, except somewhere along the line I either wired the ports incorrectly or I reassembled the wafer switches wrong.? Using an ohm meter...

Switch 1 = port 2
Switch 2 = port 1
Switch 3 = port 3
Switch 4 = zero on all ports
Switch 5 = 1.2 ohms on all ports
Switch GND = 0 ohms on all ports

Since the wafers are keyed to allow the selector shaft to enter only one way, I suspect a mis-wiring.

Thanks again to everyone for your advice.? We are very close to a fully functional unit!

John
WB0RXL

Nope. Not for sale. :D

When I can manage to get my scanner set up I am going to scan a GOOD copy of the schematic.


73

-Jim
NU0C

On Wed, 13 Mar 2024 04:06:00 +0000
"Stan Gammons via groups.io" <buttercup11421@...> wrote:

I gave my pristine condition RV75 manual to my friend, Jim, NU0C. Maybe y’all can work out something. Not meaning to volunteer you for anything Jim…

73

Stan
KM4HQE

On Tue, Mar 12, 2024 at 10:51 PM, K6OXN Bob <[bobk6oxn@...](mailto:On Tue, Mar 12, 2024 at 10:51 PM, K6OXN Bob <<a href=)> wrote:

I am looking for a copy of the original manual with the foldout schematics in the back. I try to locate original manuals if I can. Please supply availability and price plus shipping to my QTH with is good on QRZ.

73 Bob

--

73

-Jim
NU0C

I am looking for a copy of the original manual with the foldout schematics in the back. I try to locate original manuals if I can. Please supply availability and price plus shipping to my QTH with is good on QRZ.

73? Bob?

On Mon, Mar 11, 2024 at 01:07 PM, Kevin Kampman wrote:

Kevin, K8KVN

Yes, they look correct.

Contact me @billnopic@...

If you care to part with one or more.

Thanks
73
Bill
W4WCS

Any other suggestions?
Chuck

I can't take full credit. Barry N4BUQ first posted the info.

Interestingly, Tektronix appears to still use Peltola.



73

-Jim
NU0C

On Tue, 12 Mar 2024 21:51:46 +0000
"Steve Wedge, W1ES/4 via groups.io" <w1es@...> wrote:

Aha! Jim, you solved a mystery for me, as I knew I had seen those connectors somewhere else.

Steve Wedge, W1ES/4

Time flies like an arrow. Fruit flies like a banana.

Sent from [Proton Mail]() for iOS

On Tue, Mar 12, 2024 at 15:49, Jim Shorney <[jimNU0C@...](mailto:On Tue, Mar 12, 2024 at 15:49, Jim Shorney <<a href=)> wrote:

They are similar to Tektronix Peltola connectors in the way they work.



Roughly RG174 size cable with a solid center conductor that slips into a socket soldered to the board that somewhat resembles a machined DIP IC socket contact. The shield connection is a crimped ring that mates with a receptacle that reminds me of a power tube pin socket.

WA4F reportedly has some.

/g/DRAKE-RADIO/message/71107

73

-Jim
NU0C

On Tue, 12 Mar 2024 12:13:20 -0400
"Jerry Kessler" <N4JL.cw@...> wrote:

What is the name/description, manufacturer, and part number of these coaxial connectors?

Also, what is the particular coaxial cable or cables that are compatible with these connectors?



Thanks/73,



Jerry, N4JL





From: [email protected] <[email protected]> On Behalf Of Glenn Hetchler WB0DKT
Sent: Tuesday, March 12, 2024 12:01 AM
To: [email protected]
Subject: [DRAKE-RADIO] Item to check on TR7 plug-in coax connections



A friend who is a new ham and I have taken on a project TR7 in hopes of getting it on the air for him. I have enjoyed mine for 40 years.



As we were doing inspection of the plug-in boards (well aware of the many and varied connector issues) we came across an issue with a plug-in coax that I cannot remember seeing discussed before (or at least recently), so I thought I would warn others. It happened to be on the noise blanker filler board, but could have been on any of them.



That board looked untouched from the factory, so I have to believe it was built that way. The coax connector had the ground assembly that the cable plugs into, but I was stunned to see that there was no female socket for the coax center wire to plug into. It seems that because the coax was pushed at an angle from being in the shield cage, that the side force on the wire is all that made the center conductor touch the (unsoldered) plated through hole on the circuit board. There was no indication that any repair soldering (or unsoldering) had been done in that area.



Very luckily a friend who had been winding down his Drake collection a while back had offered me a few of the connector parts that he had acquired during his years of working on TR7s, as he knew I was trying to keep mine (OK, more than just one TR7 :) going. So I had exactly the center wire socket for us to push into the circuit board with a tweezers through the center of the ground connector, hold against the board with a small screwdriver and then apply solder on the bottom side. I have no idea where those connector parts could be obtained these days. If anyone does know of a supplier, please reply to this thread.



So now when inspecting the boards and their connectors, make sure the coax connectors have all their parts. If Drake forgot to install it on one board, there may be other ones out there with the same issue. It was by luck that I saw it when unplugging the coax; it would have been easy to miss.



73,

-Glenn/ WB0DKT

--

73

-Jim
NU0C

--

73

-Jim
NU0C

They are similar to Tektronix Peltola connectors in the way they work.



Roughly RG174 size cable with a solid center conductor that slips into a socket soldered to the board that somewhat resembles a machined DIP IC socket contact. The shield connection is a crimped ring that mates with a receptacle that reminds me of a power tube pin socket.

WA4F reportedly has some.

/g/DRAKE-RADIO/message/71107

73

-Jim
NU0C

On Tue, 12 Mar 2024 12:13:20 -0400
"Jerry Kessler" <N4JL.cw@...> wrote:

What is the name/description, manufacturer, and part number of these coaxial connectors?

Also, what is the particular coaxial cable or cables that are compatible with these connectors?



Thanks/73,



Jerry, N4JL





From: [email protected] <[email protected]> On Behalf Of Glenn Hetchler WB0DKT
Sent: Tuesday, March 12, 2024 12:01 AM
To: [email protected]
Subject: [DRAKE-RADIO] Item to check on TR7 plug-in coax connections



A friend who is a new ham and I have taken on a project TR7 in hopes of getting it on the air for him. I have enjoyed mine for 40 years.



As we were doing inspection of the plug-in boards (well aware of the many and varied connector issues) we came across an issue with a plug-in coax that I cannot remember seeing discussed before (or at least recently), so I thought I would warn others. It happened to be on the noise blanker filler board, but could have been on any of them.



That board looked untouched from the factory, so I have to believe it was built that way. The coax connector had the ground assembly that the cable plugs into, but I was stunned to see that there was no female socket for the coax center wire to plug into. It seems that because the coax was pushed at an angle from being in the shield cage, that the side force on the wire is all that made the center conductor touch the (unsoldered) plated through hole on the circuit board. There was no indication that any repair soldering (or unsoldering) had been done in that area.



Very luckily a friend who had been winding down his Drake collection a while back had offered me a few of the connector parts that he had acquired during his years of working on TR7s, as he knew I was trying to keep mine (OK, more than just one TR7 :) going. So I had exactly the center wire socket for us to push into the circuit board with a tweezers through the center of the ground connector, hold against the board with a small screwdriver and then apply solder on the bottom side. I have no idea where those connector parts could be obtained these days. If anyone does know of a supplier, please reply to this thread.



So now when inspecting the boards and their connectors, make sure the coax connectors have all their parts. If Drake forgot to install it on one board, there may be other ones out there with the same issue. It was by luck that I saw it when unplugging the coax; it would have been easy to miss.



73,

-Glenn/ WB0DKT

--

73

-Jim
NU0C

On 2024-03-12 09:13, Jerry Kessler wrote:

What is the name/description, manufacturer, and part number of these
coaxial connectors?

*** I'm guessing they're made by the Unobtanium corporation.
In my radio, I mostly have trouble with the outer ground clip, which gets
loosy-goosy on cables that get plugged and unplugged. Especially the
cable that comes through that hole in the DR7.

- Jerry, KF6VB

Also, what is the particular coaxial cable or cables that are
compatible with these connectors?
Thanks/73,
Jerry, N4JL
FROM: [email protected] <[email protected]> ON BEHALF OF Glenn
Hetchler WB0DKT
SENT: Tuesday, March 12, 2024 12:01 AM
TO: [email protected]
SUBJECT: [DRAKE-RADIO] Item to check on TR7 plug-in coax connections
A friend who is a new ham and I have taken on a project TR7 in hopes
of getting it on the air for him. I have enjoyed mine for 40 years.
As we were doing inspection of the plug-in boards (well aware of the
many and varied connector issues) we came across an issue with a
plug-in coax that I cannot remember seeing discussed before (or at
least recently), so I thought I would warn others. It happened to be
on the noise blanker filler board, but could have been on any of them.
That board looked untouched from the factory, so I have to believe it
was built that way. The coax connector had the ground assembly that
the cable plugs into, but I was stunned to see that there was no
female socket for the coax center wire to plug into. It seems that
because the coax was pushed at an angle from being in the shield cage,
that the side force on the wire is all that made the center conductor
touch the (unsoldered) plated through hole on the circuit board. There
was no indication that any repair soldering (or unsoldering) had been
done in that area.
Very luckily a friend who had been winding down his Drake collection a
while back had offered me a few of the connector parts that he had
acquired during his years of working on TR7s, as he knew I was trying
to keep mine (OK, more than just one TR7 :) going. So I had exactly
the center wire socket for us to push into the circuit board with a
tweezers through the center of the ground connector, hold against the
board with a small screwdriver and then apply solder on the bottom
side. I have no idea where those connector parts could be obtained
these days. If anyone does know of a supplier, please reply to this
thread.
So now when inspecting the boards and their connectors, make sure the
coax connectors have all their parts. If Drake forgot to install it on
one board, there may be other ones out there with the same issue. It
was by luck that I saw it when unplugging the coax; it would have been
easy to miss.
73,
-Glenn/ WB0DKT
Links:
------
[1] /g/DRAKE-RADIO/message/76670
[2] /mt/104879045/243852
[3] /g/DRAKE-RADIO/post
[4] /g/DRAKE-RADIO/editsub/243852
[5] /g/DRAKE-RADIO/leave/12260778/243852/767576506/xyzzy

开云体育

I don't really think this is necessary as the DR7 does not draw a huge amount of current. If you notice, the connector pins are arranged so the plug will work either way it was plugged in. Based on personal experience in a factory setting (don't ask :) ) I'm guessing that one or more DR7s inadvertently got smoked in the Drake lab so someone decided to make the connection goof-proof in the field.

73

-Jim
NU0C

On Mon, 11 Mar 2024 22:47:27 -0600
"Glenn Hetchler WB0DKT" <ghetch@...> wrote:

I have seen folks discuss that they have doubled up the power pins to the
DR7 (the connector has 4 positions, but only 2 pins are used). As I am
putting together an order for maintenance parts while working on a project
radio, I'd like to get some of those female contacts, and perhaps a spare
connector housing. Does anyone know the manufacturer and p/n of those? I
have looked in the Service Manual, but haven't been able to find where they
are listed.

Also, is a specific crimper required to install those contacts on wires, or
can tabs be bent over with a needle nose and then solder applied?

I have been able to order the Molex connectors from Mouser for the plug-ins
between the circuit boards; this request is just for the brown connectors
that plug in on the top of the DR7 board (including for front panel
switches and power transistors).

Thanks!
-Glenn/ WB0DKT

--

73

-Jim
NU0C