Re: [Drakelist] R-4C PTO Dial Mechanism Problem
Jim, I've never had the issues to know, but have you looked here? http://www.wb4hfn.com/DRAKE/DrakeArticles/PTO/Drake_PTO.htm Discusses binding PTO gears from someone oiling the nylon gear. It kind of looks like you have that going in your photos (brown water mark on your nylon gear). 73, Ron WD8SBB --- On Mon, 10/10/11, Jim DiMauro radio6...@yahoo.com wrote: From: Jim DiMauro radio6...@yahoo.com Subject: [Drakelist] R-4C PTO Dial Mechanism Problem To: Drake List drakelist@zerobeat.net Date: Monday, October 10, 2011, 10:15 PM Hi All: Looking for some help on a problem with the PTO dial mechanism of a nice R-4C that I bought some years ago but never put into service. The dials do not rotate at a constant speed, although I spin the knob at a constant speed. At a certain point in the rotation the dials abruptly speed up, then return to the slower speed until the whole works comes back 360 degrees around. Of course the dial calibration is constantly changing. Thinking it was nothing more than a dried out rubber bushing I changed it out, but it made no difference whatsoever. While observing the gear train in action I noticed that there are two gears sandwiched together, one smaller brass gear with a shaft bushing in the center, and the other a larger steel gear that rotates around the brass bushing (see photos 006 and 007 here: http://www.dcaconsulting.org/R4C_PTO/). The steel gears didn’t seem to rotate smoothly around the bushing, so I removed the dials and the gears and I can feel them bind at a certain point while rotating around the bushing that holds them together. I’m guessing that’s where my problem lies. If so, then I probably need to find a replacement gear. I’ve never been into a Drake gear train before, so I don’t know if I’m on the right track or not. Also for those of you who are familiar with the gear train, please look at all ten photos and let me know if anything obvious jumps out at you. One thing I noticed is that the kc dial disc doesn’t have a hub, but instead was just sandwiched against the brass disc on the hundreds kc dial. This is different from what I have seen in material available on the web. Any suggestions and advice would be appreciated. 73,JimW2BVM -Inline Attachment Follows- ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R-4C PTO Dial Mechanism Problem
Hi Ron: Yes, I’ve been to your site (excellent site BTW) and cleaned out the gunked up grease. The thing was a mess when I got it, with grease everywhere including the nylon gears and in between the dial plates. You’re looking at the “after” photos. Everything is nice and smooth now, except for the skipping. My setup is a bit different from the one in your photos. The “water mark” you referred to seems to be glue that holds the nylon gear onto the dial. 73, Jim W2BVM From: Ron [mailto:wd8...@yahoo.com] Sent: Tuesday, October 11, 2011 6:28 AM To: Drake List; radio6...@yahoo.com Subject: Re: [Drakelist] R-4C PTO Dial Mechanism Problem Jim, I've never had the issues to know, but have you looked here? http://www.wb4hfn.com/DRAKE/DrakeArticles/PTO/Drake_PTO.htm Discusses binding PTO gears from someone oiling the nylon gear. It kind of looks like you have that going in your photos (brown water mark on your nylon gear). 73, Ron WD8SBB --- On Mon, 10/10/11, Jim DiMauro radio6...@yahoo.com wrote: From: Jim DiMauro radio6...@yahoo.com Subject: [Drakelist] R-4C PTO Dial Mechanism Problem To: Drake List drakelist@zerobeat.net Date: Monday, October 10, 2011, 10:15 PM Hi All: Looking for some help on a problem with the PTO dial mechanism of a nice R-4C that I bought some years ago but never put into service. The dials do not rotate at a constant speed, although I spin the knob at a constant speed. At a certain point in the rotation the dials abruptly speed up, then return to the slower speed until the whole works comes back 360 degrees around. Of course the dial calibration is constantly changing. Thinking it was nothing more than a dried out rubber bushing I changed it out, but it made no difference whatsoever. While observing the gear train in action I noticed that there are two gears sandwiched together, one smaller brass gear with a shaft bushing in the center, and the other a larger steel gear that rotates around the brass bushing (see photos 006 and 007 here: http://www.dcaconsulting.org/R4C_PTO/). The steel gears didn’t seem to rotate smoothly around the bushing, so I removed the dials and the gears and I can feel them bind at a certain point while rotating around the bushing that holds them together. I’m guessing that’s where my problem lies. If so, then I probably need to find a replacement gear. I’ve never been into a Drake gear train before, so I don’t know if I’m on the right track or not. Also for those of you who are familiar with the gear train, please look at all ten photos and let me know if anything obvious jumps out at you. One thing I noticed is that the kc dial disc doesn’t have a hub, but instead was just sandwiched against the brass disc on the hundreds kc dial. This is different from what I have seen in material available on the web. Any suggestions and advice would be appreciated. 73, Jim W2BVM -Inline Attachment Follows- ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R-4C PTO Dial Mechanism Problem
Jim, After re-reading your email I do believe your problem is with the anti-backlash gear/bushing shown in your pictures 6 and 7 as you suspected. The two anti-backlash gears are suppose to be tight and not easily move on the brass bushing. I think you could probably tighten them up by placing the assy in a vise and “ peening “ the aft gear at the brass bushing with something round such as a socket or tube. The other possibility would be maybe to try and solder the bushing to the aft gear. Like I said in my previous email the gears are suppose to be tight on the brass bushing but at least one gear would need to be slightly free to move for the anti-backlash to work. The gear assy I have both gears will move on the bushing with some force applied. 73, Gary___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R-4C PTO Dial Mechanism Problem
Gary: You nailed it! Both gears move freely, except for the slight binding I mentioned in my original e-mail. I’ll have a go at securing the outer gear to the bushing. Now that you’ve described how it should work I’m confident that it will solve my problem. My concern is whether or not I’ll be able to do the fix. I’ll be leaving town this evening so I may not get to it before the weekend. I’ll be sure to post my results once I’m done with it. Not having a spare gear train to compare parts I’d have been scratching my head over this one for quite some time. Thanx much for taking the time and trouble to look into this for me. 73, Jim W2BVM From: Gary Poland [mailto:gpola...@cinci.rr.com] Sent: Tuesday, October 11, 2011 9:34 AM To: radio6...@yahoo.com; drakelist@zerobeat.net Subject: Re: [Drakelist] R-4C PTO Dial Mechanism Problem Jim, After re-reading your email I do believe your problem is with the anti-backlash gear/bushing shown in your pictures 6 and 7 as you suspected. The two anti-backlash gears are suppose to be tight and not easily move on the brass bushing. I think you could probably tighten them up by placing the assy in a vise and “ peening “ the aft gear at the brass bushing with something round such as a socket or tube. The other possibility would be maybe to try and solder the bushing to the aft gear. Like I said in my previous email the gears are suppose to be tight on the brass bushing but at least one gear would need to be slightly free to move for the anti-backlash to work. The gear assy I have both gears will move on the bushing with some force applied. 73, Gary ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Question for the group
I purchased a nice TR4 with NB for a fellow and he also tossed in two other complete non-working TR4's and an extra AC-4 and a power supply made from a Heathkit power supply and an extra RV-4. One of the non-working radios has had the chassis butchered where someone drilled a hole in the side of it and installed a toggle switch to turn the radio on and off when the switch failed. The other radio is in better shape but the receive is barely audible. The repair of the radio is out of pay grade and really not wanting to spends 50 to 100 dollars to be told it is junk. I should add both radios have the wired NB in them. The question is would I be better off trying to sell the 2 radio as complete units or piece them out and sell them for parts? Tnx and 73 Kevin - KG0MN ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Update on the search for the load cap spec for the Drake TR-7a VCXO (13.695 MHz) circuit
Ron - Too bad you didn't send that crystal from John to ICM first! They could characterize it and add it to the database. Perhaps John has another one?? :-) 73, Garey - K4OAH St Charles, IL Ron Ries wrote: Have now purchased and installed two new crystals, one at 32 pf and one at 20 pf, both were recommendations by crystal mfrs. Neither crystal would work in the circuit but John Kriner was kind snuff to sell me a used crystal which I soldered in and with minor adjustments the radio is playing beautifully. So I am now $50 poorer and none the wiser. I am sure someone has purchased a new crystal out there that has the load cap spec for this particular circuit. Ron KK7KZ ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] All band TX for the TR-7
It has been a long time (pronounced 3 DECADES ) since I did the mod on my TR7 as well. I do remember that I did a bit more looking and found that there is a male pin sticking up from the motherboard and is the transmit inhibit line (going to Q9001 as I recall). So I put a piece of spaghetti/insulation/heat shrink tubing over that male pin. That stopped it from making contact when the DR7 was plugged in. That saved having to cut that trace and then jumper the break when/if I get rid of the TR7. You want to be really careful with that mod as it allows transmitting across the entire spectrum. Prior to that mod the system would not transmit out of the band. Since the WARC bands did not exist yet when the TR7 came out those bands do not work. This mod enables transmitting in the WARC bands (AND EVERYWHERE ELSE From 1.8 mhz to 30 MHZ). If using the AUX7 then the various band segment modules could be programed to allow transmit or not allow transmit depending on the presence or absence of a diode at that pin in the module. By disabling the transmit inhibit (break the connection by cutting the trace or with insulation over the pin) you eliminate any safety net you hand that might stop you from accidentally transmitting on a frequency you were listening to outside of the ham bands. Good luck. Jim Pruitt On 10/8/2011 at 4:34 AM, wd8...@yahoo.com wrote: Guys the other week someone ask about all band TX for the TR7. Found this method in my notes on the TR7. There is another mod which cuts PCB traces which I think also disables the PLL out of lock TX inhibit. I think this method saves that function. To enable the TR7 to transmit on all frequencies 1.5-30MHz simply unsolder the collector of Q9001 on the DR7 board. See Figures 4-1 and 4-2 in the Service Manual. It's been quite some time since I was inside my TR7 looking for this mod, but seems to my my current TR7 uses this method. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R-4C PTO Dial Mechanism Problem - FIXED
Gary: I decided that I couldn’t wait until the end of the week to try the fix, so I worked on it during lunch. I soldered the aft gear to the bushing as you had suggested. All fixed, works like new. Thanx again for your trouble and advice. Ron: Although the website you pointed me to didn’t lead to the fix, thank you for taking the time to respond with a good suggestion. BTW, the TR-7 you sold me in January 2004 has been running strong, and except for a bad PIN diode the radio hasn’t so much as hiccupped. 73, Jim W2BVM From: Gary Poland [mailto:gpola...@cinci.rr.com] Sent: Tuesday, October 11, 2011 9:34 AM To: radio6...@yahoo.com; drakelist@zerobeat.net Subject: Re: [Drakelist] R-4C PTO Dial Mechanism Problem Jim, After re-reading your email I do believe your problem is with the anti-backlash gear/bushing shown in your pictures 6 and 7 as you suspected. The two anti-backlash gears are suppose to be tight and not easily move on the brass bushing. I think you could probably tighten them up by placing the assy in a vise and “ peening “ the aft gear at the brass bushing with something round such as a socket or tube. The other possibility would be maybe to try and solder the bushing to the aft gear. Like I said in my previous email the gears are suppose to be tight on the brass bushing but at least one gear would need to be slightly free to move for the anti-backlash to work. The gear assy I have both gears will move on the bushing with some force applied. 73, Gary ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] uvc divider board
Well, many thanks to all for helpful references. I was directed to eBay and purchased apparently NOS for about $1.60 each. I will let all know the results. If this is a fix, will be looking to complete the UV# with a 220 MHz module if available. Also, the 440 receives but no output. So, still some work left. Incidentally, the email /internet search robots resulted in 12 or so Chinese replies for the IC. The costs ranged from $53, to 87 cents each for a minimum quantity of 100. Most interesting. Again thanks. Will keep all posted on the progress. David Assaf, III W5XU -Original Message- From: David [mailto:w...@cox.net] Sent: Sunday, October 09, 2011 8:40 AM To: 'k4...@mindspring.com' Cc: 'drakelist@zerobeat.net' Subject: RE: [Drakelist] uvc divider board No, it is the 16 dip plastic package.Even the china references are saying they do not have any! David Assaf, III W5XU -Original Message- From: Garey Barrell [mailto:k4...@mindspring.com] Sent: Friday, October 07, 2011 9:33 PM To: David Cc: drakelist@zerobeat.net Subject: Re: [Drakelist] uvc divider board David - If it's a 14 pin DIP package the MC14016 is available from Mouser, Digi-Key and others. It's just a CMOS Quad Analog switch. Google MC14016BCP is the plastic DIP, the MC14016BCPG is the wide temperature version. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com David wrote: Looking for a MC4016P for a UV3 divider board. This is an obsolete part. Any sources? David Assaf, III W5XU - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1831 / Virus Database: 2085/4543 - Release Date: 10/07/11 ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] NB-4
I suspect the noise blanker in my R-4C is not working. How can I definitively test it? 73 de W3NU ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] All band TX for the TR-7
On Tue, 11 Oct 2011 08:15:10 -0700, Jim Pruitt wrote: It has been a long time (pronounced 3 DECADES ) since I did the mod on my TR7 as well. I do remember that I did a bit more looking and found that there is a male pin sticking up from the motherboard and is the transmit inhibit line (going to Q9001 as I recall). So I put a piece of spaghetti/insulation/heat shrink tubing over that male pin. That stopped it from making contact when the DR7 was plugged in. That saved having to cut that trace and then jumper the break when/if I get rid of the TR7. The same thing can be accomplished by clipping the insulated jumper wire on the (old version) digital control board. Exactly the same as the Q9001 mod. A seperate trace cut on the digital control board is required to enable TX coverage in the 2.5 and 5.0 MHz bands. As noted before, this method preserves the Out Of Lock TX disable signal, which the mod published by DRAKE does not! For this reason, I do not recommend doing it the official Drake way, and have in fact removed that mod from a couple of rigs and re-did them with this method. Interestingly, my TR-7 had been all-banded with the Q9001 mod, and I had noticed that it didn't TX in the 2.5 and 5.0 bands, but never gave it any thought because there weren't ham frequencies there at the time. Now, of course, there is a 5 MHz allocation. 73 -Jim -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime. HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] NB-4
On Tue, 11 Oct 2011 23:27:24 -0400, Charles Ring wrote: I suspect the noise blanker in my R-4C is not working. How can I definitively test it? I have tested noise blankers in the past by wiring up a relay to a variable power supply through one of it's own normally closed contacts to make it chatter, then adjusting the power supply for a slow chatter in the range of typical automotive ignition noise. A clip lead antenna on one of the relay connections is sometimes necessary. Impluse noise such as this should almost disappear with a good noise blanker. Atmospheric or constant noise, not so much. I've never tested an R-4C blanker this way, but in principle it should work. 73 -Jim -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime. HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Drake TR-4C Fil. Vol. Response To Comments
Hello All, Thanks for the several comments received re this problem (?). To VK2IFT: That's the easiest approach and I shall probably do as you suggest. To WA8ULW: The 'just under 6V' can be taken as 6V. The Manual does call for 6.3V. Do not know, at this stage, how far 'out of spec' the HV is. I do have a copy of an AC-4, built in N.Z. many years ago. It would be interesting to see what filament/HV it delivers. It made here, probably, because of our 50 Hz Mains and was possibly cheaper than importing them from the USA. To WD8SBB: This was rather an interesting proposal but, I think I will be leaving 'well enough alone'. Especially if I can get over 100W out. To W1ES/4:We have 50 Hz down here and I agree, 'tube equipment', tends to be less fussy than solid state. T0 WB6KBL: All the tubes in the TR-4C have indirectly heated cathodes, so I don't know if I will get extended tube life. I had originally thought that lower filament voltage would have resulted in lower electron transfer but this would only apply to a directly heated cathode (I think). However, with indirectly heated cathodes, the lower filament voltage will result in lower wattage heating the cathode (about 4.75% lower). However, like W1ES/4 says, 'fire it up and see what power comes out'. Once again, thanks for all the comments, they made interesting reading and I always learn something. Bob ZL2AAQ ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
