Posts: 14
Threads: 3
Joined: May 2018
City: Alexandria
State, Province, Country: Louisiana
I am working on my mom and Dad’s (both now deceased) 40-180. I had it working a while back, decided to clean up and restore the cabinet which turned out great. When I learn how to post pictures, I’ll be showing it off!! I was getting ready to put the chassis back in, but first wanted to check everything. I had to replace the 7G7 (1232) because
As I was pulling the radio out of my shop I saw the old 7G7 lying on the floor with the glass broken off! Got a new 7G7 and here’s the problem:
Tried to pu the new tube in the socket, but it won’t go in completely. Not enough to make a good connection anyway. Looked for obstructions, but didn’t see any. Made sure the tube was going in properly, nothing. Cleaned the pins on the tube with 0000 steel wool, nothing. Cleaned the pin receptacle in the cocker, nothing. Sprayed the socket with WD-40, still nothing. The ring that goes around the metal piece to hold the tube in, may be obstructing, but can’t tell.
I don’t necessarily want to change the socket but may have to, so need to know of someplace to get another socket.
Help!!!
Posts: 15,835
Threads: 554
Joined: Oct 2011
City: Jackson, NJ
Look for bumps on the bottom of the new tube. If the old one went in, so should the new. Look at the key.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 14
Threads: 3
Joined: May 2018
City: Alexandria
State, Province, Country: Louisiana
I agree that if the old one went in, the new one should too. I found the old tube on the floor when I moved the radio. Not sure how that happened. Thinking now perhaps the locking mechanism has slipped? Perhaps the metal ring that acts as a spring has slipped around?
Posts: 15,835
Threads: 554
Joined: Oct 2011
City: Jackson, NJ
Inspection in cases like this one is the best way to see what is happening. See if another loctal tube fits in the socket. If not, then it is the socket. If yes, then it is the tube. All loctals are the same.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 696
Threads: 8
Joined: Apr 2018
City: S. Dartmouth
State, Province, Country: MA
Occasionally, repairs (soldering) to socket pins causes solder to flow in areas where it causes a mechanical obstruction..
Try inserting the tube, be sure key is aligned, from below while observing the socket from the underside. blades of the pins and the lock ring will all move slightly if as the tube is inserted. If a pin contact does not show movement then it is likely there is an obstruction.
I don't envy loctal socket replacement, it is difficult to find new sockets and an RF stage is usually crammed with critical components. You may have to re-align if there is a disturbance to the wiring...
YMMV
Chas
Pliny the younger
“nihil novum nihil varium nihil quod non semel spectasse sufficiat”
Posts: 14
Threads: 3
Joined: May 2018
City: Alexandria
State, Province, Country: Louisiana
I examined the loktal this morning and still couldn’t see an obstruction. Acting on a hunch, I pressed down on the little circular spring keep where the center guide pin goes. The spring popped out, which I went ahead and picked up. Tried putting the tube in the socket and it went in. The socket doesn’t have the locking mechanism, but it appears it will work fine. Will power up the radio later today to see if it is still working.
Posts: 2,118
Threads: 112
Joined: Jun 2010
City: Medford OR (OR what?)
Forceful removal of a loctal tube will often damage the socket. Since your tube was broken, it is safe to assume that it was knocked out of the socket (forceful removal). the little bump on the side of the base indicates the direction to rock the tube in a normal removal.
Besides the propensity of the sockets and tube pins to oxidize, the damage to sockets is a major failure cause of loctal tubes. You may be able to reinstall the spring. The short, skinny pins usually make proper function of the lock important.
"I just might turn into smoke, but I feel fine"
http://www.russoldradios.com/