开云体育

*** I see a cracked solder joint right at the ceramic endpiece. Never did find the similar problem with my TR7 - The PTO would go to 1/10th its normal output, disabling the synthesizer. You'd tap on

Yup Frank Krozel Life Member, ARRL (630) 924-1600 kg9hfrank@...

I had one in a PTO, too! Every now and then, its level was way down and the R4C's sensitivity with it... Hitting on the side of the RX would cure it for a while. But... thou shalt not beat your

Today we had 30 check-ins to the net. We had the following radio's used for the check-ins. TWINS - 5 TR3 = 2 TR4(x) = 5 TR5 = 4 TR7 =7 Next week Bill W9MXQ will be the NCO. 73's, Mark, WB0IQK

Gary & Group, More info- Suspecting that I slagged my finals, I looked in the cage. Saw a fresh solder blob near the base of the choke and a lead popped out from one of the parasitic choke resistors.

Group, I'm looking for a list of bona-fide Drake C-Line repairers. Tnx & 73 Jay W6CJ

Solder connections can develop fractures that are hard to see even with magnification. I had one in a PTO that was only visible from a certain angle, otherwise the connection looked good. "Richard

Yes, by all means, Congratulations on the fix! Sometimes I’ve had that happen to me, too. I wonder if sometimes I scare the radio into working. Mike, WB8VGE www.theheathkitshop.com

Congratulations! Its fairly common for their to be cold solder joints that look fine. Sometimes they show up if you poke around the circuit with an insulated stick like a chop stick. -- Richard

I tried the 6EH7, which is similarly the same pin out with lower gain. Performance of the receiver was seriously degraded. W1ES

The tube has so much gain that it picks up noise like crazy. I can move a metal tool around the base of the third mixer and hear changes in the noise level. Way too sensitive. W1ES

The 6EJ7 is pretty common and can be had for a couple of bucks at a ‘fest or for around $5 at the various tube sellers. I have the advantage of having a fairly nice inventory of tubes used on Drake

I tested contacts, inductance and resistance in all parts used on 40 meters only. While doing so I lifted all leads that might affect the measurements. This brought 40 meters back to life. Miracles

Besides the difficulty of selecting a quiet 6EJ7 tube, the circuit design is flawed. The earlier 6HS6 mixer has the 5695 kHz IF tuned circuit directly connected to the grid, and the LO fed to the

Please try 6BX6 in place of 6EJ7 (My injection method by LA8AK). 6BX6 has half Gm as 6EJ7, yet same pin connection. You can try 6BX6 without soldering. I would appreciate any feed-back. Yuichi JA3XKJ

The power supply that is the subject of this issue is the 7805 regulator on the VCO board. That is the one that denies power to just the one VCO (high bands, in this case) when it fails. Regards, Gary

The WB4HFN website has a section with great information related to that power supply board. I just used it to resurrect a TR7 that was DOA. Good luck. 73 Tony N5DIM

Sounds like you are on the right track. Don’t ocelot the electrolytic capacitors on that supply as well. Gary W0DVN

Gary, I found a few minutes to work on the TR7 and discovered that the high VCO is not working at all. It does have the 10 vdc supply switch on it but I don't know if that reulagor is working or not.

It seems to me that the 6EJ7 was one of the first frame grid tubes. Supposed to be magic but then turned out to have problems. -- Richard Knoppow Los Angeles WB6KBL SKCC 19998