开云体育

Since we started discussing meter shunt resistors in another thread, I took a look at those in my TR-4 and I'm a bit confused on the color codes. R45 is designated as 2 ohms on the schematic. The color bands on mine are red, black, yellow, yellow. I think possibly one of those yellow bands indicates a 4% tolerance but not sure what the other yellow band means. Ordinarily I would have seen that to as a 200k resistor but that's obviously not correct. R13A in mine is a 27 ohms. Measuring across R45 and R13A, I get about 2.2 ohms. If R45 was initially 2 ohms, then 27 ohms across it would have dropped that to about 1.8 to 1.9 ohms. I'm guessing that the 0.2 to 0.3 ohms is very negligible but can't help but wonder - especially with those rather odd color-codes on R45. Probably better off to leave this one alone since I doubt the meter itself would be sensitive to such small changes, right? Thanks, Barry - N4BUQ

Well, after a year I have decided to make alignment to a couple of SPR-4 that I have. I have already made the first step 50 khz if BFO and adjusted T17 for zero beat. Problem start here: I have been trying adjusting T15 and T16 but no deflection at all in the S-meter, in both receivers, I have no scope but I have an analog voltmeter that could help instead of the S-meter. Im consulting some notes gathered from this link, and I am looking at the S-meter instead of connecting a VTVM as the manual indicates: https://www.zerobeat.net/drakelist/drakemod/drmod101.html As I said before I cannot get the signal level , S3-S5 , that indicates, Anyone has had this problem before? Any help is greatly appreciated. Note , I am using a TinySA signal generator , maybe am I doing something wrong?

Hello everyone. I am new here. Let me know if I become too much of a pain ... I just received a Drake 2B from an eBay seller. I will admit to a lot of stupidity on my part and a lack of understanding before I pushed the "Purchase now" button. I purchased this during an emotional stupor because I was looking for a GOOD old tube SW receiver like my Dad used when I was in elementary school in the 60s - a Hallicrafters S-40B. Mom and Dad were scrimping by with just barely enough money and my Dad picked-up that Hallicrafters from a junk yard and got it working again. Even though Dad had to walk a mile to work and back because he did not have a car, he gave some priority to buying that Hallicrafters. And we had a great time listening to stations all over North and South America late into the night (usually ending only when Mom came into the room with her hands on her hips). I remember the glow on the ceiling and the smell of those hot tubes. So, after reading a lot of reviews which all kept focusing on the Drake 2B as THE radio to have, I pushed that eBay button and have been waiting where my driveway meets the street ever since. It showed up yesterday and I unboxed it and started reading the manual. Boy, am I ever lost! I am not normally a stupid fellow and I can usually get my brain to cooperate on new and even difficult concepts, but that manual and me have decided to part company. Surely, there is a better source of information somewhere on how to work this radio! I have more questions than I believe this group will allow, but let me start with this one: If I understand the manual correctly, and a little simple math, if I purchase ten crystals and fill each of the ten slots, that will give me a total band spread of frequencies of (let's see: a 600 kHz spread per crystal, times ten crystals, equals 6,000 kHz of total frequencies) available on this radio. Of the frequencies usually collectively available on the LW, MW, and SW bands on most of these old vintage radios (specifically, .5 to 30 MHz), this radio will not tune to the LW or MW groups and will let me listen to only 6 MHz (6 MHz!) of the SW group. Is that REALLY true? Surely a coveted radio with owners' comments centering around "I will never give it up" to "I should not have given it up" can do better than that! Is this true, or will someone here tell me where the secret button is that will allow me to tune in the remainder of the HF field? Really, I think I goofed and bought a specialized radio that was never intended to be in the hands of a "general receiver" fool. Richard W2ONE By the way, ever since I unboxed the radio and started sighing heavily with each page turned in that manual, my wife has started standing at the door with her hands on her hips...

Can someone please tell me what is meant by the term "soft finals"? I'm still having problems getting proper output from my TR-4 and, for all I know, that might be the problem. I've tested them for transconductance and all three are very close to the same value and, furthermore, that value is quite a bit above the minimum for a good tube. Aside from low output (i.e. about 300 mA plate current maximum into a dummy load), I notice that if I hold down the key for a few seconds the plate current tends to drop just slightly and I think if I were to continue holding the key down, the current would continue to slowly decrease. I measured the voltage across each cathode resistor and I notice the same phenomenon: the voltage climbs to about 1.6 VDC and then begins to drop a bit. Like the transconductance values, each cathode resistor is "matched" in value and behavior to the other two so I suppose that's one good thing. Am I seeing the result of weak/soft tubes or is something else going on that would cause this? Thanks, Barry - N4BUQ

I have for sale a Heathkit TC-1 Tube Tester. If you need a basic tube emission tester, this is a pretty decent one. I replaced the Selenium rectifier and the 0.1 uF capacitor. I also replaced the cracked grid/plate cap wire. I cleaned the switches. It works as it should. It looks very good too. $90 plus shipping. Gary W0DVN

Hello all. I’ve been out of the ham hobby for 47 years and very rusty in everything. I have an old Drake 7077 Microphone I need to wire for my TR4C. Can someone help me with the wiring please? 73s Ralph AD9FM