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Re: T-4XC problem
Most of the time, it¡¯s a matter of adjusting the VOX and antiVOX gains, which can be a bit touchy.? Note also that the VOX settings for CW and phone are separate.? Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana. Sent from for iOS On Tue, Jan 21, 2025 at 10:41, Barry KJ5GQM via groups.io <chasbg@...> wrote:
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Re: T-4XC problem
Try it with the mic disconnected to make sure it's not the mic that has a problem.? You can switch it to x-cw without the mic to see if the relay sticks.? The relay can get sticky.? You can remove it and GENTLY take the clear cover off so you can spray some deoxit in there.? Be careful putting the relay back in because you can easily bend the pins on the relay or the blades in the socket.? I had this same problem with my TX-4Cw when I first got it and cleaning the relay with deoxit fixed the problem.
On Tuesday, January 21, 2025 at 09:22:11 AM CST, Steve G8GSQ via groups.io <g8gsq@...> wrote:
I'm looking at a T4XC for a friend. It needed new output tubes when he got it, they showed overheating marks on the plates and the cathode resistors were burnt out. With replacements fitted and the neutralising adjusted it seemed to work fine.
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A few weeks on he's reported a problem; transmitting on SSB ok, but on releasing the PTT it sometimes stayed in tx and the only thing he could do was turn the power off. I asked if he had the VOX on, he said thought not, and operated the switch to check. It went straight onto tx and now goes to tx the moment power is turned on, regardless of the VOX switch or mic gain settings.
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Has anyone seen this problem before? Any suggestions on possible culprit circuits?
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Thanks and 73,
Steve G8GSQ
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T-4XC problem
I'm looking at a T4XC for a friend. It needed new output tubes when he got it, they showed overheating marks on the plates and the cathode resistors were burnt out. With replacements fitted and the neutralising adjusted it seemed to work fine.
?
A few weeks on he's reported a problem; transmitting on SSB ok, but on releasing the PTT it sometimes stayed in tx and the only thing he could do was turn the power off. I asked if he had the VOX on, he said thought not, and operated the switch to check. It went straight onto tx and now goes to tx the moment power is turned on, regardless of the VOX switch or mic gain settings.
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Has anyone seen this problem before? Any suggestions on possible culprit circuits?
?
Thanks and 73,
Steve G8GSQ |
Re: Relay for Drake L4B
Might try Harbach Electronics or Nationwide Radio.
On Tuesday, January 21, 2025 at 10:02:24 AM EST, Ronnie Hull - W5SUM via groups.io <w5sum@...> wrote:
Does anyone know of a drop in replacement for the relay in a L4B?
Or do you know the specs? Drake manuals give little to no information.
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Ronnie W5SUM
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Re: Drake repair service
The Tr7 is really pretty simple to troubleshoot and repair. There's a lot of people out there more than capable. it's not just two or three in the whole world.
On Monday, January 20, 2025 at 09:43:14 PM EST, David via groups.io <david.w5xu@...> wrote:
I have a Hunter Bandit?on the bench.? I will check that out as well. David Assaf III W5XU, VP8RXU ? On Mon, Jan 20, 2025 at 8:38?PM Jim Shorney via <jimNU0C=[email protected]> wrote:
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Re: T-4XC has a "condition"
¿ªÔÆÌåÓýHi guys, ? It¡¯s been a few weeks since we had an update. If you go back and review the thread most of the concern was with the T-4XC tune up procedure, knob left, knob right, never heard of that¡.. ? My original thought was the bias setting was never correct from the power supply. So I bought an upgrade two board kit and gave the AC-4 new life. Yes, I had a problem and that¡¯s the reason for the delay. ? Today I received a new fuse, 5A slo blo and hooked up the rigs and¡. First order was to run the POTA list on 20 meters. Got every one of them. Then realized the grey line was here so went to 15 meters and worked Nori in Japan, no problem. ? Conclusion: I could not correctly tune the T-4XC because the bias was wrong in the PS. ? Thank you for all the help. ? Dean/ N2TNN ? From: [email protected] <[email protected]>
On Behalf Of Gary WB6OGD via groups.io
Sent: Friday, January 3, 2025 7:32 PM To: [email protected] Subject: Re: [DRAKE-RADIO] T-4XC has a "condition" ? On Fri, Jan 3, 2025 at 12:28 PM, VE7PS wrote:
If there is a difference (there should NOT be), it probably indicates the need for neutralization.? 10meters is where the final can most easily break into oscillation if not neutralized properly (and with a correctly working transmitter). ? I would set the bias on the lower bands, and on SSB with the gain at zero... and after I nulled the carrier!? If the radio is working correctly, that bias point should hold on all bands, if it doesn't something is wrong. ? 73, Gary WB6OGD ? ? ? ? |
Re: Drake repair service
I have a Hunter Bandit?on the bench.? I will check that out as well. David Assaf III W5XU, VP8RXU ? On Mon, Jan 20, 2025 at 8:38?PM Jim Shorney via <jimNU0C=[email protected]> wrote:
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Re: Drake repair service
Interesting. I've never seen that configuration. Granted, I have not worked on every amp out there. But all I have seen is the single reverse biased diode. My two Alpha amps have it, and W8JI also shows a single diode. I'll stick with the single diode method.
On Mon, 20 Jan 2025 00:38:59 -0800 "Jim VE7RF via groups.io" <jim.thom@...> wrote: On Sun, Jan 19, 2025 at 03:41 PM, Jim Shorney wrote:With the 2nd diode installed (rvs connected pair).....the pair? ensures the B-? ?can't wander more than? +/-? .7 vdc? ?from chassis potential.? ?In the old days, something like a 10 ohm resistor from B- to chassis? would accomplish the same thing.? The concept in both cases was to float the B- from chassis potential just enough..... to be able to measure plate and grid current.? The issue with the 10 ohm resistor is if the anode arcs to the grid, or chassis, the fault current path is up from the chassis, through the resistor.... and back to the B- of the filter caps..... completing the loop.....and of course the resistor grenades.Interesting video but his glitch diode configuration has me puzzled. Hecomplains (rightly so) that the B- was returned to the chassis but -- 73 -Jim NU0C |
Re: T4XC Power Output?
Thanks Jim, I think the IFR1200S reads 150 watts, but you're right.?? I should get a dry dummy load for the shack. 73 On Mon, Jan 20, 2025 at 6:28?PM Jim Shorney via <jimNU0C=gmail.com_at_groups.io_lastradioman@...> wrote:
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Re: T4XC Power Output?
Richard, Thanks for the info and drive levels document.?? I'll check that out.? I have a service monitor with basic scope functions. 73, Jay (OT: my QTH is 4-5 miles SW of the nearest part of the Eaton fire at its peak.? We had masks on indoors and air purifiers at max for two days) On Mon, Jan 20, 2025 at 6:06?PM Richard Knoppow via <1oldlens1=ix.netcom.com_at_groups.io_lastradioman@...> wrote: ? ? I suggest going over the RF and mixer stage adjustments. I am going |
Re: T4XC Power Output?
Thanks Tim. It was a noninductive load in an IFR-1200S service monitor. 73 Jay On Mon, Jan 20, 2025 at 5:28?PM amfone via <amfone20000=yahoo.com_at_groups.io_lastradioman@...> wrote:
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Re: T4XC Power Output?
I suggest going over the RF and mixer stage adjustments. I am going more by experience with a T4XB but they are not much different from the C. It is normal for the power output to be slightly lower on the high bands than at 80 and 40 but those two should be about the same. If you have run out of range on the trimmer caps but the slugs are where they should be try using a slightly lower or higher frequency for the adjustments. This is often necessary for 160. Note that the power in TUNE is different than the power in CW. The ALC limits maximum power to about 120 watts but does not operate in Tune or CW. For CW you may be able to get as much as 150 watts out but its usually best to tune in TUNE for slightly lower power. On 10 meters, with RF and mixer adjusted properly you should be getting around 90 watts.
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Test in CW mode and see what you get. I am attaching a document with T4XB drive levels on it. The C should be about the same. It may help. I don't have a note as to the source of this but thought it worth saving. It is very strange that even though I drive quite a lot I have seen very little sign of the fires. L.A. is a very strange city. Dystopia indeed. On 1/20/2025 4:41 PM, Jay W6CJ via groups.io wrote:
Group, --
Richard Knoppow Los Angeles WB6KBL SKCC 19998 |
Re: T4XC Power Output?
Jay I'd say all is normal or close to it other than 3550. Now was that into a 50 ohm? nonrestrictive load? Nothing to be concerned about actually no one will tell the difference on the receive end. Tim WB8UHZ
On Monday, January 20, 2025 at 07:42:10 PM EST, Jay W6CJ via groups.io <lastradioman@...> wrote:
Group,
While making a cheat sheet for pre-tuning my T4XC (see attached excel doc), I noticed low power out on some frequencies - especially 3550 Khz.? ?What is normal power output on the traditional & WARC bands? A W4 wattmeter was used. 73 from the LA dystopia? ? ?? Jay W6CJ |
Re: TR-4C Problems with 28.0 and 28.5 bands
This is a long-shot. Try adjusting T1. Steve Wedge, W1ES Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Monday, January 20th, 2025 at 3:40 PM, Dave KD5FX via groups.io <land.dave@...> wrote:
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Re: TR-4C Problems with 28.0 and 28.5 bands
Yes, I have tried switching the Xtals all around. I first put the 28.0 Xtal in the 29.1 slot and got nothing, no receive. I then put the 28.5 Xtal in 29.1 and got the same, nothing. Then I put the 29.1 Xtal (which works OK when in the 29.1 slot) in the 28.0 and 28.5 slots and got nothing. So that was strange, the problem didn't move, still no receive on 28.0 and 28.5.?
A friend suggest using my SDR to listen to the V1 oscillator freq and see what I was getting. So I made a sampler probe with a short piece of coax and a small coil of wire and only needed to get it close to V1 to get a strong signal.? I started with 7.0 band which is 21.5 MHz and the 21 band which is 35.5 MHz and got good strong signals on the SDR with both bands. On 29.1 I am getting a strong signal at 43.6 MHz but 28.5 (43.0 MHz) and 28.0 (42.5) had nothing. So I set it to 28.5 band and tweaked the L5 control I was soon able to get a signal near the proper 43.0 MHz but not exactly, it would be just below that and then as I turned it just a bit more it would skip over and be above 43.0 by a few KHz. I could never get it right on 43.0. However, when I hooked the Drake back up to an outside antenna I am now getting SSB signals across that 28.5 band! But the dial is off by about 20 KHz. So that's better than nothing on that band! 29.1 band is still working normally and 28.0 band is not working at all, I could never get it to tune up and oscillate. Perhaps that Xtal is bad.?
I temped to just quit there, it's working except for 28.0 band.?
73, Dave KD5FX
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Re: The Hum-Less 2B
Good point. I¡¯d find a way of using the slots.? I don¡¯t mind using the Hayseed kits for sets that I¡¯m keeping. I am, however, beginning to use my Sprague TO-6 to test the caps after I unhook the wires. I have found that most of the receivers and earlier TR-4¡¯s have can caps in them that still pass testing by a comfortable margin.? The most troublesome can caps I have found are on the TR-4C(any) and the T-4(any). Any TR-4C sets that cross my bench will get new caps if they don¡¯t have them replaced already.? Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana. Sent from for iOS On Mon, Jan 20, 2025 at 08:46, John K5MO via groups.io <johnk5mo@...> wrote:
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Re: 4-Line Crystals for 10M
That was me and thank you! Bill N1WL
On Monday, January 20, 2025 at 12:04:34 AM EST, n4buq <n4buq@...> wrote:
I think someone was having problems with two of the 10M bands with a 4-line rig recently.? I happened to see these and thought I'd pass the ad along: Thanks, Barry - N4BUQ |