#662

My?Tuna Helper ][+ is experiencing issues with the T/R switching & after mucho troubleshooting my board looks a bit hacked as I touched up quite a few solder joints & changed out Q1, etc. I have the PN2222A pin out so I know it goes backwards to the silkscreen layout, but I changed it anyway since the first time around I installed it the other way automatically (never transmitting until this weekend), even though I read the instructions saying otherwise. Basically I seem to loose signal switching after the intersection of the 1K & 47K resistors. I measured with my RF probe, then removed the 47K part to doublecheck as the 2.2uF cap influences the measurement big-time.

How much transmitter power is needed for the T/R switching to work? I should hear the relay click & return depending on the Fast or Slow jumper settings, but Q1 is not switching at all. I measure 0.8 volts B to E, & 12.45 volts at the collector. I assume 300mw is enough TX power, but that could be an issue also that I did not consider. The PWR/OP SPDT switch works great as that is how I measured TX power originally.

I knew I had an issue as the Mute function on my Tuna Helper seems to mute my Icom comm. receiver all of the time when I plug in the RCA jumper. I could easily reverse the logic on the relay once I get it to switch with real QRPp TX power. But first I need Q1 to switch so that one side of the relay coil goes low to cause it to click over.

I have an older non-+ version of this kit unbuilt, I might build it up as well for comparison. Then take RF probe readings to compare.

Cheers,

Davey --KU9L?

#663

开云体育

Davey,

Hey, send me your phone number and a good time to chat and I'll solve ALL your problems...

Rex? ??? W1REX

On 1/28/2024 7:47 PM, David Knapp via groups.io wrote:

Show quoted text

My?Tuna Helper ][+ is experiencing issues with the T/R switching & after mucho troubleshooting my board looks a bit hacked as I touched up quite a few solder joints & changed out Q1, etc. I have the PN2222A pin out so I know it goes backwards to the silkscreen layout, but I changed it anyway since the first time around I installed it the other way automatically (never transmitting until this weekend), even though I read the instructions saying otherwise. Basically I seem to loose signal switching after the intersection of the 1K & 47K resistors. I measured with my RF probe, then removed the 47K part to doublecheck as the 2.2uF cap influences the measurement big-time.

How much transmitter power is needed for the T/R switching to work? I should hear the relay click & return depending on the Fast or Slow jumper settings, but Q1 is not switching at all. I measure 0.8 volts B to E, & 12.45 volts at the collector. I assume 300mw is enough TX power, but that could be an issue also that I did not consider. The PWR/OP SPDT switch works great as that is how I measured TX power originally.

I knew I had an issue as the Mute function on my Tuna Helper seems to mute my Icom comm. receiver all of the time when I plug in the RCA jumper. I could easily reverse the logic on the relay once I get it to switch with real QRPp TX power. But first I need Q1 to switch so that one side of the relay coil goes low to cause it to click over.

I have an older non-+ version of this kit unbuilt, I might build it up as well for comparison. Then take RF probe readings to compare.

Cheers,

Davey --KU9L?

#664

Rex,

I will send it to your email. In the meantime I have built a new Tuna Tunah ][+ and the older version (3" can?) of the Tuna Helper ][ that both work wonderfully.?

Problem #2: I paused with the Tuna Tunah ][+ as I removed the relay and the RCA connector, but still have the short on the board on the MUTE side of the relay.?

Problem #1: When I discovered the transistor does not have to be reversed on the newest version, I replaced the PN2222A correctly with one of my spares, however, the transistor still does not switch. I was about to replace the 1N4148 that I may have damaged with the transistor being backward, but still looking in my junk box for one. In the meantime, the older version of the TH T/R switch is working great. I want to get the newer version working for the Super Tuna ][+ which will be online here in a few more weeks when I have a chance to finish it.

Thanks,

Davey -- KU9L

On Thursday, February 1, 2024 at 11:37:09 AM EST, Rex Harper <tunacankits@...> wrote:

Davey,

Hey, send me your phone number and a good time to chat and I'll solve ALL your problems...

Rex? ??? W1REX

On 1/28/2024 7:47 PM, David Knapp via groups.io wrote:

My?Tuna Helper ][+ is experiencing issues with the T/R switching & after mucho troubleshooting my board looks a bit hacked as I touched up quite a few solder joints & changed out Q1, etc. I have the PN2222A pin out so I know it goes backwards to the silkscreen layout, but I changed it anyway since the first time around I installed it the other way automatically (never transmitting until this weekend), even though I read the instructions saying otherwise. Basically I seem to loose signal switching after the intersection of the 1K & 47K resistors. I measured with my RF probe, then removed the 47K part to doublecheck as the 2.2uF cap influences the measurement big-time.

How much transmitter power is needed for the T/R switching to work? I should hear the relay click & return depending on the Fast or Slow jumper settings, but Q1 is not switching at all. I measure 0.8 volts B to E, & 12.45 volts at the collector. I assume 300mw is enough TX power, but that could be an issue also that I did not consider. The PWR/OP SPDT switch works great as that is how I measured TX power originally.

I knew I had an issue as the Mute function on my Tuna Helper seems to mute my Icom comm. receiver all of the time when I plug in the RCA jumper. I could easily reverse the logic on the relay once I get it to switch with real QRPp TX power. But first I need Q1 to switch so that one side of the relay coil goes low to cause it to click over.

I have an older non-+ version of this kit unbuilt, I might build it up as well for comparison. Then take RF probe readings to compare.

Cheers,

Davey --KU9L?