Re: [Drakelist] R4A on an inverter
On Jul 20, 2011, at 7:55 AM, Neil M Califano wrote: The power consumption of the R4a is 60 watts and I'd like to run the radio off my 12 volt car cigarette lighter using a 130 watt PSW inverter. I think the fuse is 10 amps. So 12.5 volts x 10 amps=125 watts. But I heard of fuses blowing running only laptops. It looks good on paper, but practically will this work? Probably not. 1. The inverter is rated 130VA (you can look up the reason why, and what a VA (volt amp) is, but suffice it to say that a 130VA inverter will max out (and possibly go fizzle pop without a good fuse or overload protection at 91 watts. That is of course assuming that it's a 130VA inverter in the first place, based on the specs you gave it it's 130VA INPUT. 2. The inverter is barely 50% efficient. If you are lucky, you can run a 65 watt laptop off of it, but probably not. My GUESS is that it's 91 Watts input and 30-40 watts out. 3. The R4a uses 60 Watts (or so) with the volume set at a reasonable level. That's how things were rated in those days. It may draw a little more with a loud station, and often draws less BUT it's a tube radio. Tubes draw lots of current when cold and as they warm up draw a lot less. So if for a short time the tubes draw 100 watts, or 200 watts, or even 300 watts, no fuse will protect your inverter, it will be toast. 4. Inverters are just switching power supplies. They put out lots of noise and so on. The really cheap ones put out square waves instead of smooth sine waves, and you won't be able to hear anything over the noise. Geoff. -- Geoffrey S. Mendelson, N3OWJ/4X1GM Making your enemy reliant on software you support is the best revenge. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] RV-7 External VFO Problem
Ed, Make sure that you put the RV7 switch in the correct position(s). If you did, then proceed. If you didn't even have lights, I would check the bulb. Take it out and make sure it lights on 12 volts from a small power supply. If the bulb lights, then I would look at the jones socket on the TR7 to see that it has the correct voltages present. Look at the schematic of the RV7 to see which socket pins has the +12 volts and ground. 73 Ron WD8SBB --- On Tue, 7/19/11, rfch...@verizon.net rfch...@verizon.net wrote: From: rfch...@verizon.net rfch...@verizon.net Subject: [Drakelist] RV-7 External VFO Problem To: drakelist@zerobeat.net Date: Tuesday, July 19, 2011, 6:57 PM A buddy of mine who knew that I was going to a hamfest this past Sunday asked me to pick up an RV-7 external VFO for use with his TR-7. I saw one at an agreeable price, was assured by the seller that it was in working condition, and I purchased the RV-7. When I connected it to my TR-7A is was as dead as a doornail! Absolutely nothing. Anyone have any suggestions before I start to really tear into the RV-7? I checked the obvious, eg. connections inside the Jones plug, looked carefully for any broken wires or missing componenents, etc. Any help would be appreciated. Tnx 73 Ed K2ZE -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] R4A on an inverter
Try it and see! If it doesn't work, get the next largest size they're all pretty cheap right now. The power supply for my laptop is 90W and I've got a small-ish road warrior laptop! John K5MO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] PTO Question and Drake 4C Questions
If you put a lubricant on the nylon gears, they will swell and bind !!! Do not lubricate the nylon gears, metal ones are OK to lubricate. Also, do not bang the nylon gears at their end stops. It will distort the gears. (OK to do this if you have to w/metal gears) Lee, w0vt From: Paul Christensen Sent: Wednesday, July 20, 2011 9:52 AM To: drakelist@zerobeat.net Subject: Re: [Drakelist] PTO Question and Drake 4C Questions Thanks for the PTO advice. I do recall hearing that the C line had a nylon gear version and a metal gear version. I think the metal gears were on later builds?? I suppose there is no real way to tell without opening the cabinet and looking inside. Operationally, I don't notice a difference but I much prefer the feel of the metal geared PTOs in the C Line. The all-Nylon assemblies seem a bit sloppy during quick rotation. But that does not affect the drive to slug, only the dial gears. On the PTO, you said 'regular motor oil... is fine on the bearings. So it sounds like the Drake PTO is not greased up like the Collins PTO, just some oil on soem bearings. Are those just nylon or plastic sleeve bearings or an actual bearing? You'll probably get many recommedations on this one. I've recently used Daven oil on the worm drive and Lubriplate on the ball bearing raceway. Since you'll likely not find Daven oil, it's similar in substance to what watch repair shops. Being a Daven product from the days when broadcast consoles used ladder attenuators, the oil helps to preserve electrical conductivity. I don't own a C line yet as I am just starting to pursue one. I want to get a late model setup and eventually acquire the full station except the transverters and converters. I've got a lead on a local one that hasn't been used since 1994. Seller emailed some photos and I'm awaiting answers to some questions about filters, extra crystals, crystal and filter covers, corrosion, serial numbers, etc.. I think once you're up around the 26,500 serial number, you're probably okay with the metal gears but you need to ask the owner. That's the only reason why I would pursue a late production R-4C. If you proceed with Sherwood mods or other customization, it doesn't make much sense to hold out for a 29K+ unit unless you want to preserve it intact for historical preservation purposes. Both my B and C lines are heavily modified around the first mixer, power supply, and everything changed from the product detector to the headphone jack. I doubt I would do this to a mint receiver. I took average looking equipment and made them mint through new knobs, dial lenses, VFO knob with inlay, cabinet screws, painting by Hartzell, etc. It does not take much to make a cosmetically mint receiver with all the recourses available. If you have a lead on a nice later model C line I'd appreciate hearing about it. I think there's a nice one on the big auction place right now with many of the Sherwood mods. Paul, W9AC ___ 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] PTO Question and Drake 4C Questions
- Original Message - From: Paul Christensen w...@arrl.net To: drakelist@zerobeat.net Sent: Wednesday, July 20, 2011 7:52 AM Subject: Re: [Drakelist] PTO Question and Drake 4C Questions Thanks for the PTO advice. I do recall hearing that the C line had a nylon gear version and a metal gear version. I think the metal gears were on later builds?? I suppose there is no real way to tell without opening the cabinet and looking inside. Operationally, I don't notice a difference but I much prefer the feel of the metal geared PTOs in the C Line. The all-Nylon assemblies seem a bit sloppy during quick rotation. But that does not affect the drive to slug, only the dial gears. On the PTO, you said 'regular motor oil... is fine on the bearings. So it sounds like the Drake PTO is not greased up like the Collins PTO, just some oil on soem bearings. Are those just nylon or plastic sleeve bearings or an actual bearing? You'll probably get many recommedations on this one. I've recently used Daven oil on the worm drive and Lubriplate on the ball bearing raceway. Since you'll likely not find Daven oil, it's similar in substance to what watch repair shops. Being a Daven product from the days when broadcast consoles used ladder attenuators, the oil helps to preserve electrical conductivity. I don't own a C line yet as I am just starting to pursue one. I want to get a late model setup and eventually acquire the full station except the transverters and converters. I've got a lead on a local one that hasn't been used since 1994. Seller emailed some photos and I'm awaiting answers to some questions about filters, extra crystals, crystal and filter covers, corrosion, serial numbers, etc.. I think once you're up around the 26,500 serial number, you're probably okay with the metal gears but you need to ask the owner. That's the only reason why I would pursue a late production R-4C. If you proceed with Sherwood mods or other customization, it doesn't make much sense to hold out for a 29K+ unit unless you want to preserve it intact for historical preservation purposes. Both my B and C lines are heavily modified around the first mixer, power supply, and everything changed from the product detector to the headphone jack. I doubt I would do this to a mint receiver. I took average looking equipment and made them mint through new knobs, dial lenses, VFO knob with inlay, cabinet screws, painting by Hartzell, etc. It does not take much to make a cosmetically mint receiver with all the recourses available. If you have a lead on a nice later model C line I'd appreciate hearing about it. I think there's a nice one on the big auction place right now with many of the Sherwood mods. Paul, W9AC I don't know what was in Davenoil but one can get very highly refined special oils from the Nye company, they have a web site. I've used their oils on camera shutters and other delicate mechanisms. Becareful of oiling or greasing Nylon or Delrin gears, they absorb some oils which cause them to swell and crack. There are special greases for use on plastic gears. One is made by La Belle and sold in shops that sell model railroad stuff. Collins recommends an aircraft grease for use on the metal gears in some of its equipment. I got the right grease as Aeroshell Grease No.7 Other greases should be cleaned off before applying it as it reacts with some to form a hard substance. In fact, a couple of air crashes were traced to this. -- Richard Knoppow Los Angeles WB6KBL dickb...@ix.netcom.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] (no subject)
Continuation from last night: If I attempt to run a R4A from a pure sine wave 130 watt inverter, can I ruin the inverter or just blow a fuse? If it's just a fuse, I give it a try. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] R4A from car inverter
Continuation from last night: If I attempt to run an R4A from a pure sine wave 130 watt inverter, can I ruin the inverter or just blow a fuse? If it's just a fuse, I'll give it a try. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] PTO Question and Drake 4C Questions
The TR-7 nylon gears are not affected by oil because the gear bushings are brass on brass. The older PTO's used a nylon gear over a brass bushing and oil is a problem. I have had to disassemble many older 4 line PTO's with binding gears and open up the hole in the nylon gear with a wood dowel and sand paper. 73, Gary ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
