loose 1500 antenna connector

Doug Seyler

I have a Flex 1500 that I bought pre-release at Dayton. I have had a recurring problem with a loose antenna BNC connector. The first time, it was fixed gratis, then next time close to $100 bucks, and it is loose again. I talked last year at Dayton to the guy who designed the transceiver and he admitted that the solder area isn't big enough on the early units to adequately solder the connector. I would have hoped for a strong mechanical attachment. I now use an RG-58 jumper to the rig but still it is again loose and intermittent. Haas anyone else had this problem with their Flex 1500, or an I just especially cursed?

Max_VE3TMT

1. Remove the 4 screws off the back panel
2. Remove the 2 screws from the 9 pin Flexwire connector
3. Remove the 4 screws from the front panel
4. Remove the 4 bottom feet.

There are two boards in the enclosure, attached through a header pin and socket. They simply pull apart. You will have to remove the shield from the RF board to get access to the bottom of the antenna connector. This involves the removal of two screws that secure the transistors to the shield. Once removed the shield will drop off. When reassembling, it's a good idea to add more heat sink grease if required. Note the position of the shield when removing, it has to go on the same way for the feet to reattach. Also when reinserting the PCB's back into the enclosure, make sure they line up with the panels before attaching the feet.

I don't think just soldering is strong enough to prevent the same thing from happening again. On the component side of the board, I scraped away some of the PCB coating to get at the copper around the BNC jack. I then soldered the jack to the board which really beefed it up. I then applied small gobs of JB Weld to both sides of the connector and PCB to really secure it. After sitting for a couple of days, I doubt I'll ever have this issue again!

Max

John

I have not looked inside mine as yet, but I want to remove the BNC and replace it with a pl-259 if there is enough space. Has anyone got a pic of the inside mounting of the flex3000 bnc socket?

Dale KB5VE

Unfortunately that type if issue shows up on some modern transceivers as they get smaller and compact. I would consider a pigtail with a so239 on it like some of the ultra small dual ganders. A strain release would be required also. I have had two of the 1500's and no issue but could see where there could be. .

Ernest

I used my 1500 for many years and never had an issue with the BNC connector.
I took many trips with the radio in my laptop computer carry-on bag; and as you may know TSA is not a very gentle inspecting your bags.
May I suggest that you do not over tighten the connector with so much un-necessary pressures. Or passed the nipples on the BNC receptor.

vectorizer

For the record, I also had a loose antenna BNC connector. I made it worse as a newbie by using a stiff jumper cable. Tried to "repair" it myself, and stuffed little pieces of paper in it to reduce juggling. Before I started taking the 1500 out on the road in VHF contests, I decided to send it back to Flex for a proper repair. Hasn't come loose again despite a lot more abuse and connecting/disconnecting than I did when I just used it at home. FWIW.

Doug Seyler

Thanks, it's good to know that others have had the same problem. After three trips back to Flex, my connector is finally rock solid.

Max_VE3TMT

Old thread, but mine has now failed twice. I looked at the connector and there is not much support for the ground portion of the connector. I plan on enlarging the ground solder area and then JB Welding the connector to the board. I guarantee this is the last time that connector will come loose. It is a PITA to repair, you have to completely take the Flex apart to separate the two circuit boards to get at the antenna connector.

Max

VE3TMT

Doug Seyler

Yea, I talked to the designer of the 1500 at Dayton one year and he admitted that the connector ground pad on the early radios (mine is S/N 534) was not substantial enough. I've had it repaired 3 times, once on Flex and twice on me, and it is loose again. I saw a thread where a guy took a tiny piece of heat shrink tubing and put it between the connector and the housing. I'm going to look into that. I really don't want to completely disassemble the RF deck.

Good luck, Max!

Doug W9LCQ

Max_VE3TMT

The repair appears to have been a success. I did scrape some coating of the PCB and resoldered the ground connection. The ground tab on the opposite side of the connector seems to have snapped which explains why it broke again so easily. I did bond it with some JB Weld, so I imagine after a couple of days it will be pretty solid. Got the radio all back together again and started making contacts. Now I have RF in the audio on 40m, must have disturbed the shack cabling putting everything back together. That will be another project.

Max
VE3TMT

Doug Seyler

Congratulations Max. Perhaps that will give me courage to tackle disassembling the rf deck myself.

Doug

Max_VE3TMT

1. Remove the 4 screws off the back panel
2. Remove the 2 screws from the 9 pin Flexwire connector
3. Remove the 4 screws from the front panel
4. Remove the 4 bottom feet.

There are two boards in the enclosure, attached through a header pin and socket. They simply pull apart. You will have to remove the shield from the RF board to get access to the bottom of the antenna connector. This involves the removal of two screws that secure the transistors to the shield. Once removed the shield will drop off. When reassembling, it's a good idea to add more heat sink grease if required. Note the position of the shield when removing, it has to go on the same way for the feet to reattach. Also when reinserting the PCB's back into the enclosure, make sure they line up with the panels before attaching the feet.

I don't think just soldering is strong enough to prevent the same thing from happening again. On the component side of the board, I scraped away some of the PCB coating to get at the copper around the BNC jack. I then soldered the jack to the board which really beefed it up. I then applied small gobs of JB Weld to both sides of the connector and PCB to really secure it. After sitting for a couple of days, I doubt I'll ever have this issue again!

Took the whole station apart and reassembled one piece at a time to find out where the RF was coming from. Some additional grounding solved the problem.

Max

Doug Seyler

Thanks for the details. It doesn't sound too bad, so I'll give it a try. I've had the boards out before, and stopped just short of removing the heat sink.

73,

Doug