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Drake SPR-4 50 Khz IF and 50 Khz Filter alignment 17
I am trying to make a full alignment to a Drake SPR-4 but I have come across with an issue in the first step that the procedure manual indicates, any guidance would be greatly appreciated. According to the point 5.3.1. I have connected a VTVM and the signal generato where indicated, I can adjust T17 for zero beat but when adjusting T15 and T16 for maximum deflection there is no a slight movement neither in the voltmeter nor in the S-meter. Due to the high impedance of the circuit , could be causing this the FET and IC located in the S-meter PCB? I have seen modifications that recommend to replace them: http://www.zerobeat.net/drakelist/drakemod/drmod101.html Anyone has had this problem before? Or could be caused by other elements.
Started by enriqueeeeee2001 @ · Most recent @
Understanding Receiver Sensitivity 15
The TR-4 manual states the receive sensitivity should be "less than 1/2 microvolt for 10 db S+N/N." The manual also states that each S unit on the S-Meter corresponds to approximately 5 DB. If I establish a reference point on the S-Meter for just noise, then feeding a 0.5 uV voltage into the antenna jack should, at a minimum, increase the S-Meter by two units. Is that an oversimplification? If so, what is a better way to measure S+N/N. I seem to recall that when I was doing that for the Collins R390As I had, I was using an audio level meter (TS-585) and using AM detection to measure the increase so maybe that's a better way (although, sadly, I no longer have that TS-585). Thanks, Barry - N4BUQ
Started by n4buq @ · Most recent @
FS ¡ª AC-4 4
You just saw it in a previous post. This one came in with a mid-late C Line, with a cut cord. Since I had to replace the cord and test it, I tried my ¡°new¡± (to me) use of a gland strain relief. All voltages good, tested with a TR-4 after verifying voltages. Supply hums a little (the supply itself ¡ª not the audio). This is an original supply that has not been rebuilt. I can rebuild for an extra $150, including parts. $120 plus shipping from central NC (27253). Also have an MS-4 that is decent for $50 plus shipping. Shipped separately from AC-4, of course. The rest of the C Line will be available but not for awhile. The transmitter needs to be revived and receiver is pretty grotty. Receiver is mid-Late with a full deck of CW filters, Sherwood mixer and power supply upgrades. 73, Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana. Sent from Proton Mail for iOS
Started by Steve Wedge, W1ES/4 @ · Most recent @
TR-3 no xmit 80-20
Okay, this one is strange. I may have bodged something and may need ¡°second sight¡±. I had to replace V1 socket because I ruined one pin whilst removing resistors. Rebuilt using a socket from a parts rig and reconnected everything, as far as I know. Xtal oscillator adjustment went fine. Peaked 40, 15 and 10. Receive is great on all bands. 10 doesn¡¯t elicit S meter response but receive is strong. For an early set, receive is fine. Transmit is the opposite of what most people see: 15 and 10 are pretty good. 20 and lower are almost nothing. It was providing plenty of power before the repair. Now ¡ª it¡¯s QRP. Counter sees correct frequency but power out is nearly nil. Reading the rotary switch diagrams is torture. Anything jump out at any of you? Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana. Sent from Proton Mail for iOS
Started by Steve Wedge, W1ES/4 @
Glands for power cords 4
Per the previous thread on ways to replace the oversized 2-wire AC cord in the AC-4, I¡¯ve found the perfect part: no drilling, no special tools, just pass an 18 AWG 3-conductor cord through the gland, solder the wires to the appropriate terminals, pass the gland through the existing hole without enlarging tighter and Bob¡¯s yer uncle. Yes, 18 AWG is sufficient, as it can safely be used up to 10A. It took me as long to snap the pic and post it here. If you¡¯re still concerned that the power cord isn¡¯t ¡°beefy¡± enough, look at the size of the conductors that follow inside the AC-4. 73, Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana. Sent from Proton Mail for iOS
Started by Steve Wedge, W1ES/4 @ · Most recent @
TR3/4 Meters 31
I'm working on a TR-3 with the dreaded "bouncy meter". I have one plate amperes meter. These can't be swapped because they're mirror image of each other but noticed that the deflection is different in each. Does anyone know what these meters are calibrated to (i.e., what is FS current for each)? Also, if anyone has a spare S meter, please let me know if you're interested in selling it. 73, Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana. Sent with Proton Mail secure email.
Started by Steve Wedge, W1ES/4 @ · Most recent @
Filament fuse blew 21
I was trying to re-seat the LSB bulb to the chassis because the bulb was intermittent. In doing so I think the positive side of the bulb housing touched ground some how because when I turned the TR-4CW back on and the amp meter light, frequency light, LSB, and USB lights were not lit. Then the filament fuse blew! I replaced the wire with #26 AWG and pulled both LSB and USB out and re-seated them and made sure nothing was shorting to ground. I quickly turned on the rig but still those lights would not light. The only light that I get is the round red light on the right side of the frequency read out. I connected my power supply to my other TR-4CW and that rig works OK so the power supply is still good. Not sure what is going on? Mark
Started by Mark N2DMI @ · Most recent @
R4B Crystal Calibrator 3
Hi, Turned on my R4B calibrator, bad hum, them puff. Bad 1000 uf electrolytic in the 12v. line. Changed it, voltage ok, but dead. Suspect IC. Been looking, but cant find them. Anyone know a source? May stick in a small calibrator board I have instead, thoughts? Ed W1FU
Started by Edward w1fu @ · Most recent @
Strain Relief for AC-4 8
Rather than spending time trying to reinvent the wheel, have any of you installed 16 AWG SJT power cords into an AC-4 using the correct strain relief? I understand that this will involve enlarging the hole in the AC-4 but I'm done with Dremeling strain reliefs to get them to work with round cables. Too much time and I have a few AC-4's that need at least an updated AC cord. Yes, 16 AWG is smaller than factory 14AWG 2-conductor but a 5A continuous load is fine with a 16 AWG cord. It's more important, at this point, to have a safety ground for the power supply. What size relief and what size hole? 73, Steve Wedge, W1ES Time flies like an arrow. Fruit flies like a banana. Sent with Proton Mail secure email.
Started by Steve Wedge, W1ES/4 @ · Most recent @
Panel Spacer for 2-B and 4-Line 2
Hey Everyone, I¡¯m restoring a 2-B and would like to get an update on panel spacer availability. Some time ago, 2bradioparts.com stocked spacers that he had labeled as being for 4-Line radios; I compared one these to the a spacer installed that is in good shape, and it is the same size, while the new one looks to be plastic instead of fiber, which is fine. Does anyone know a source for these spacers nowadays? The new uncompressed thickness is 2.6 mm. See photo. Thank you, Michael Smith, N4KZO
Started by Michael Smith @ · Most recent @
Drake 1A Receiver 9
I have a 1A, Serial #331, an early one, and another later one with WWV. I didn't realize that the original version did not have a crystal calibrator (I knew it didnt have WWV) until I opened them both up for recapping. The "newer" one also has a couple of sub boards, the original does not, though the components seem to be there. I don't have and cannot find the manual or a schematic for the older unit, just for the newer one from BAMA. My question is does anyone know what the WWV mod, (which could be performed by Drake) consisted of? I assume it was not a difficult mod, and that the bandswitch has another contact for WWV. I have replaced the tuning dial with another I had, which has the WWV marking. Was thinking of adding the calibrator and WWV mod, but since no schematic of original old version its not obvious what was added. I have a third unit Which works but missing knobs and face place, its a shame to use it as spare parts. Thanks, Ed W1FU
Started by Edward w1fu @ · Most recent @
Drake 1A receiver Speaker 4
i have seen pictures of a matching speaker for the 1A in advertising, but have never actually heard of one. Did they actually produce it? It looked like it used (or would use) the same 1A cabinet. Was thinking of making one as I have another cabinet, but did they actually exist? I use a 2A speaker, which looks good. Thanks, Ed W1FU
Started by Edward w1fu @ · Most recent @
For sale: Drake L4B and power supply. Very good condition. Eimac 3-500 tubes. 1200 watts output with 100 watts drive. $1,000 shipping extra. 3
-- This email has been checked for viruses by Avast antivirus software. www.avast.com
Started by Rich W3RJ @ · Most recent @
For sale: Drake L4B and power supply
For sale: Drake L4B and power supply. Very good condition. Eimac 3-500 tubes. 1200 watts output with 100 watts drive. $1,000 shipping extra. W3RJ -- This email has been checked for viruses by Avast antivirus software. www.avast.com
Started by Rich W3RJ @
6JB6A 9
Gentleman: For a TR-4C, is there any difference between 6JB6A brands? I'm buying 3 of them and there's some well known brands available such as Sylvania, GE and RCA. RCA a bit cheaper. All NIB/NOS. Any recommendations? 73 Marcus PY2PLL + PY3CRX GG66rf
Started by Marcus PY2PLL @ · Most recent @
Current meter does not move when setting load during tune up. 2
When tuning up my second TR-4CW the current meter goes to 0 when I push in the load control to tune it. I can see the load control working on my external power meter just nicely. I figured it was the switch. I measured all 3 terminals on this switch compared to my other TR-4CW (that doesn't have this issue) and my ohm measurements are pretty close so I believe the switch is OK. Not sure what to do next? Mark
Started by Mark N2DMI @ · Most recent @
WRL- Galaxy IO Group
There is an IO group devoted to Leo Myerson's equipment. Leo made a huge impact on amateur radio. If you have an interest, please join us at: /g/WRL-Galaxy-Radios Tnx, Dale W4OP
Started by Dale Parfitt @
TR-4 AM Mode 18
On my TR-4, when I switch to AM mode I get no audio output at all. Can someone please suggest a way to troubleshoot this? I thought that if I touched the grid of the last audio amplifier with a screwdriver, I'd get a pretty loud buzz, etc., from the speaker but I don't get anything with that little test (crude, yes, but I was trying to see where the signal stopped). I presume injecting a modulated CW signal back through the chain should eventually find where it stops but not sure about that. Any hints are welcome. Thanks, Barry - N4BUQ
Started by n4buq @ · Most recent @
Drake C Line For Sale 3
Hello all, I am selling one of my Drake C Lines: R-4C, T-4XC with manual AC4, MS-4 and fresh cables. All stock, very good condition, and regularly on the air. For the time being, pickup only in Arlington, VA. $550. tks, Burt W3IO
Started by Burt W3IO @ · Most recent @
File /RCA_CA3053.pdf uploaded #file-notice
The following items have been added to the Files area of the [email protected] group. /RCA_CA3053.pdf By: Jim Shorney <jimNU0C@...> Description: RCA CA3053 differential amp IC data sheet
Started by Group Notification @
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