View Full Version : Twins
Look what I traded my IC-R75 for:
http://i815.photobucket.com/albums/zz79/gyrogeerloose/draketwins.jpg
They need a bit of cleaning and TLC but are in good, restorable shape. I've wanted a set of Drake Twins ever since I first got interested in ham radio when I was a teenager and forty years later I finally got 'em. I am a happy camper.
I wanted a TR-7/R7 'set' back in high school but the entire station (with options) cost ~$9,000 in those days.
Weren't no way I could have swung THAT. Just the transceiver with filters and NB7/AUX7 was north of $2k!
Times change. Radios break and people can't figure out how to fix them, so on the block they go.
At the moment there are 7 R7s in and around my shack. Four work. Three have to be rebuilt, and I'm trying to get Tony Mills (of 4CFrontpanels) to repro the R7 panel as he's done with the TR7/L7 setup.
Have fun with that setup. Be sure to keep an eye out for a nice SW4A and/or an SPR4 to go along with it.
Nice. Very nice.
I do miss my C-Line, but like my Hallicrafters station, it's time came and went. Maybe one day, but not today.
Same deal with the twins—way out of my price range back in the day.
One of the reasons I sprung for the set was that they are something I actually have a chance of being able to repair myself. No way I can work on modern equipment, it's just far too complex for me. Vacuum tubes, point-to-point wiring and discrete components, though, that's the sort of stuff that was still current (although already on the way out) when I got what little formal training I ever got in electronics so I might be able to deal with it. It helps that there's a lot of info online and pretty much all the electronics parts are easily obtained.
If you need spares (especially toobz) they're yours for the asking - same goes for any other Islander who's in need of a part to get his or her rig back in service. Ye Olde Junque Box continues to grow at a rate far faster than I can utilize it so if it didn't cost me anything it won't cost any of you either.
If you need spares (especially toobz) they're yours for the asking - same goes for any other Islander who's in need of a part to get his or her rig back in service. Ye Olde Junque Box continues to grow at a rate far faster than I can utilize it so if it didn't cost me anything it won't cost any of you either.
Okay, thanks!
The caps in the power supply will need probably to be changed out, the thing has apparently been sitting for a while. Which reminds me that I need to call my buddy and ask if I can borrow his Variac.
I don't know about the tubes yet—I haven't done anything more than a quick visual inspection to make sure that everything was there—but if you have a pair of the 6JB6 television sweep tubes the transmitter uses as finals, I'll happily buy them from you. If I don't need them now, I will eventually.
KB3LAZ
07-03-2011, 09:45 PM
Nice mate
suddenseer
07-04-2011, 09:07 AM
One more item to complete your vintage station.
http://www.universal-radio.com/used/u681lrg.jpg
They are easier to work on as well. If my memory serves me the AM mode of Drake radios sounded a bit funky. Some of the ancient mary enthusiasts have developed mods to cure that. Good find!!
w2amr
07-04-2011, 10:59 AM
Nice find Carl. Now keep ur eyes peeled for one of these.
http://www.hug-a-bug.com/FS4.html
KG4CGC
07-04-2011, 11:06 AM
Wow Carl. Did you realize how large this project would grow?
Wow Carl. Did you realize how large this project would grow?
In a word, yes. I'm not really into collecting radios—except for vintage Drake stuff and have had my eyes set on accumulating a station for a while now. I'll be looking for an MN-2000 or MN-4 next, once I have some actual disposable income.
w2amr
07-04-2011, 12:55 PM
Wow Carl. Did you realize how large this project would grow?We have no problem helping brother Carl spend his money.
...but if you have a pair of the 6JB6 television sweep tubes the transmitter uses as finals, I'll happily buy them from you. If I don't need them now, I will eventually.
Those are the one type I'm fairly sure that I don't have but I'll look. Had 6LQ6, 6JE6 and a few similar one years ago - not sure if they're gassy at this point.
Be on the lookout for:
7075 (re-branded Turner Plus 3) mic
W4 wattmeter
C4 station console with CC2/CC6 transmitting and SC2/SC6 receiving converters. I have one each of the latter plus the attendant power supply if you want them.
Those are the one type I'm fairly sure that I don't have but I'll look. Had 6LQ6, 6JE6 and a few similar one years ago - not sure if they're gassy at this point.
No biggie, they are still pretty easily found and there are alternatives should they ever become scarce. How is your supply of electrolytic cans, though? I imagine I'll have to replace the filter caps in the power supply.
Be on the lookout for:
7075 (re-branded Turner Plus 3) mic
W4 wattmeter
C4 station console with CC2/CC6 transmitting and SC2/SC6 receiving converters. I have one each of the latter plus the attendant power supply if you want them.
I was kind of wondering what kind of mic I should get for the thing. I don't think the Heil iCM I use on the IC-736 would be a good match. As for the other items, I definitely want them, I just don't have the money to buy them right now. Should that happen to change in the near future, I will drop you a line.
Very sweet indeed Carl!
I love the older gear but 7-lines (and a few Kenwood/Yaesu hybrids) are all I have room for at the moment. If we get ourselves another house with the right style of basement (read: 60+ feet, full) I'm going to put the contesting stuff on one wall and a vintage lineup on the other.
KA9MOT
07-05-2011, 07:08 AM
Those are the one type I'm fairly sure that I don't have but I'll look. Had 6LQ6, 6JE6 and a few similar one years ago - not sure if they're gassy at this point.
Be on the lookout for:
7075 (re-branded Turner Plus 3) mic
W4 wattmeter
C4 station console with CC2/CC6 transmitting and SC2/SC6 receiving converters. I have one each of the latter plus the attendant power supply if you want them.
I have the W-4 Watt meter. Someday I'd love to put the rest of the station together...as it is the W-4 alone is the most beautiful thing in the shack.
Nice score Carl!!!!
W1GUH
07-05-2011, 09:59 AM
Somebody mentioned a variac:
I've got way more than I can use, I wound up with a collection getting "almost right" variacs. They're all 3 or 5 amps...about the right size for bringing up old stuff. They're free to anyone who can meet me at a hamfest. Might even be willing to ship. Now I gotta go get 'em all together to see what I've actually got!!!
Or....they seem to be common and cheap ($5 to $10) at hamfests.
Enjoy that gorgeous 4-Line!
KC2UGV
07-05-2011, 10:22 AM
Nice set of twins there... I've been on the hunt for a set of tube-twins myself :)
Somebody mentioned a variac:
I've got way more than I can use, I wound up with a collection getting "almost right" variacs. They're all 3 or 5 amps...about the right size for bringing up old stuff. They're free to anyone who can meet me at a hamfest. Might even be willing to ship. Now I gotta go get 'em all together to see what I've actually got!!!
Or....they seem to be common and cheap ($5 to $10) at hamfests.
Enjoy that gorgeous 4-Line!I'll take you up on one of those variacs, next time we can get together. I can use one for my Swan 3Drifty.
Somebody mentioned a variac:
I've got way more than I can use, I wound up with a collection getting "almost right" variacs. They're all 3 or 5 amps...about the right size for bringing up old stuff. They're free to anyone who can meet me at a hamfest. Might even be willing to ship.
I'll pay for shipping if you're up for the hassle of standing in line at the post office...
W1GUH
07-05-2011, 11:51 AM
Probably something I can get thinking about doing. I'll take inventory this weekend -- there's probably 2 in my car -- and let you know if this is do-able, and I think it is. Maybe it's not such a hassle; the P.O.'s right down the block. I'll PM you when I've got things organized.
I finished the cleanup and cosmetic restoration of the T-4X and it looks pretty nice. Now, as long as I can get it to, you know, actually work...
http://i815.photobucket.com/albums/zz79/gyrogeerloose/t4x.jpg
The R-4A will be done pretty shortly.
w2amr
07-22-2011, 01:03 PM
I finished the cleanup and cosmetic restoration of the T-4X and it looks pretty nice. Now, as long as I can get it to, you know, actually work...
http://i815.photobucket.com/albums/zz79/gyrogeerloose/t4x.jpg
The R-4A will be done pretty shortly.
Very nice. Are you going to replace the filter caps in the P/S? Probably would be a good idea.
Very nice. Are you going to replace the filter caps in the P/S? Probably would be a good idea.
Yeah, probably. There's a kit available.
BTW, I realize that I should have included a "before" pic, so here it is:
http://i815.photobucket.com/albums/zz79/gyrogeerloose/t-4xbefore.jpg
Somebody mentioned a variac:
I've got way more than I can use, I wound up with a collection getting "almost right" variacs. They're all 3 or 5 amps...about the right size for bringing up old stuff. They're free to anyone who can meet me at a hamfest. Might even be willing to ship. Now I gotta go get 'em all together to see what I've actually got!!!
Or....they seem to be common and cheap ($5 to $10) at hamfests.
Enjoy that gorgeous 4-Line!Ever find those variacs?
w2amr
07-22-2011, 02:57 PM
Yeah, probably. There's a kit available.
BTW, I realize that I should have included a "before" pic, so here it is:
http://i815.photobucket.com/albums/zz79/gyrogeerloose/t-4xbefore.jpg
How is the paint on the cabinets, ok?
KG4CGC
07-22-2011, 02:59 PM
I finished the cleanup and cosmetic restoration of the T-4X and it looks pretty nice. Now, as long as I can get it to, you know, actually work...
http://i815.photobucket.com/albums/zz79/gyrogeerloose/t4x.jpg
The R-4A will be done pretty shortly.What is your preferred solution of knob wash?
K7SGJ
07-22-2011, 03:17 PM
Whipped Cream in a slow circular motion.
What is your preferred solution of knob wash?
Denatured alcohol, then a buff with the Moto Tool followed up by a hand polish with some jeweler's rouge on a cotton cloth. I re-whitened the lines, too, which really made 'em pop.
How is the paint on the cabinets, ok?
It's not bad. There are a few scratches but not enough to make me feel like I need to repaint them. They're never going to be museum quality or anything but they'll sure look nice in the shack once I'm finished with them.
KG4CGC
07-22-2011, 03:22 PM
Denatured alcohol, then a buff with the Moto Tool followed up by a hand polish with some jeweler's rouge on a cotton cloth. I re-whitened the lines, too, which really made 'em pop.
Usually Windex™ here unless I need something stronger and then I go with diluted Purple Power™ or Simple Green™.
Your method is clearly superior.
w2amr
07-22-2011, 04:04 PM
It's not bad. There are a few scratches but not enough to make me feel like I need to repaint them. They're never going to be museum quality or anything but they'll sure look nice in the shack once I'm finished with them.I used to do the cabinets of my Drake gear with Armor all. It gave them a nice satin finish.
Ever find those variacs?
Funny you should ask—I just got one from a buddy this morning. It's a big ten amp unit, but just the bare variac itself, which reminds me of a question I wanted to ask here: obviously, it needs to be mounted in a case to mitigate the shock hazard but what should it be made of? Is plastic good enough or should it be metal for shielding or heat resistance?
K7SGJ
07-22-2011, 05:11 PM
All the ones I have had and seen usually had metal cases. A few old ones had bakelite. I think the metal are a lot stronger. I have a 220 one out back that is all metal and heavy as hell.
Re: Drake cabinet refinishing -Ron, WB4HFN has a nice writeup on his site. When I get home I'll update this post with a link.
ETA - as promised:
http://www.wb4hfn.com/DRAKE/DrakeArticles/TechTips/CabinetRepainting.htm
KA9MOT
07-22-2011, 08:03 PM
I've always wanted a set of twins. Since I was a young man....Blond, Brunette, Red Head....doesn't matter..
Now I am old and gray and so are all the twins my age......Gray, Blue, or White......doesn't matter.....
:lol:
Nice job on your Drake.... I'd like a set of those too..... or Kenwood twins.
K7SGJ
07-23-2011, 01:13 AM
It won't be much longer berfore his twins will be keeping him up all night.
w2amr
07-23-2011, 04:11 AM
Usually Windex™ here unless I need something stronger and then I go with diluted Purple Power™ or Simple Green™.
Your method is clearly superior.I'm with you. I use a nice mild cleaner like windex, even if I have to use it several times. I've seen how heavy duty cleaners like 409 0r spray 9 can distroy the paint on an old front panel.
Just got an e-mail message from a local ham buddy who heard I'm working on a set of Drake twins. It turns out that he's got an MN-4 antenna tuner that he got in a trade but never used. It's just been sitting in his garage and he'll let me have it for cheap. I haven't seen it yet so I don't know what kind of shape it's in but if it's at least restorable, I may have have another addition to the Drake collection without even trying.
http://www.eham.net/data/reviews/images/1854.jpeg
w2amr
07-23-2011, 01:01 PM
Just got an e-mail message from a local ham buddy who heard I'm working on a set of Drake twins. It turns out that he's got an MN-4 antenna tuner that he got in a trade but never used. It's just been sitting in his garage and he'll let me have it for cheap. I haven't seen it yet so I don't know what kind of shape it's in but if it's at least restorable, I may have have another addition to the Drake collection without even trying.
http://www.eham.net/data/reviews/images/1854.jpegThe quest for Drake accessories has begun. Yer in trouble now.:snicker:
The quest for Drake accessories has begun. Yer in trouble now.:snicker:
I know. The only thing worse than having an itch to collect stuff is not having the money necessary to scratch it...
KG4CGC
07-23-2011, 02:26 PM
MN-4 should be a good tuner and restorable assuming you don't have to deal with much corrosion. Avoid an MN-7 though.
KA9MOT
07-23-2011, 02:30 PM
I keep seeing the W-4 Watt meters for sale for around $75. I got mine in a trade, and it is the best looking piece of equipment I have.
I keep seeing the W-4 Watt meters for sale for around $75. I got mine in a trade, and it is the best looking piece of equipment I have.
I've seen a couple go on fleaBay for around $40-50 over the past couple of days. It's tempting, but since I already have a Bird Model 43 wattmeter, kind of hard to justify at the moment.
W1GUH
07-25-2011, 07:06 AM
Mil pardon about being so pokey about the variac(s). Took inventory & it's not as good as I thought. One of 'em had no brush, gave it away at a hamfest to get it out of the way. That leaves a 3A and a 1A...not sure how useful those would be.
Re: Drake Power supplies...
If the T-4 uses the AC-4, here's a super way to re-cap it, courtesy of the Heathkit Shop (http://www.theheathkitshop.com/page7/page7.html). I re-capped an AC-3 with that and it's a great thing, makes the job easy. Even if it isn't the AC-4 you need to recap, that kit probably has what you need.
MN-4 should be a good tuner and restorable assuming you don't have to deal with much corrosion. Avoid an MN-7 though.Out of idle curiousity, why? What's the issue with an MN-7?
Mil pardon about being so pokey about the variac(s). Took inventory & it's not as good as I thought. One of 'em had no brush, gave it away at a hamfest to get it out of the way. That leaves a 3A and a 1A...not sure how useful those would be.
< snip >No worries. It was a thought.
I actually have a small variac, but it belongs to K4NQA (ex KA3NQA) who loaned it to me before he moved away. One of these days, we have to get together and exchange it (he has my Ameco AC-1T). I hope to either have another one, or be done working on my Swan 3drifty by then.
Mil pardon about being so pokey about the variac(s). Took inventory & it's not as good as I thought.
No worries—I got one locally, a 10A unit.
If the T-4 uses the AC-4, here's a super way to re-cap it, courtesy of the Heathkit Shop (http://www.theheathkitshop.com/page7/page7.html). I re-capped an AC-3 with that and it's a great thing, makes the job easy. Even if it isn't the AC-4 you need to recap, that kit probably has what you need.
Yeah, thanks, I found out about the Heathkit Shop via WB4HFN's The Drake Page (http://www.wb4hfn.com/DRAKE/DrakePageHome.htm). It's a great resource for vintage Drake equipment info.
W1GUH
07-25-2011, 01:15 PM
I've seen a couple go on fleaBay for around $40-50 over the past couple of days. It's tempting, but since I already have a Bird Model 43 wattmeter, kind of hard to justify at the moment.
The MN-4 would look hamsexy next to the twins, but I'd pass on one. But then, I'm a real stick-in-the-mud about the only tuner is a balanced tuner!
Drake stuff sells easily:
I got an MN-7 "for free" when I got the TR-7, RV-7 last year and it was taking up space in my back seat ever since. So at the Sussex hamfest I decided to try to sell it. It literallly flew out of my arms. I hadn't even set it down yet when a guy looked at it....said $50? Exactly the number I was thinking.
KG4CGC
07-26-2011, 03:33 PM
Out of idle curiousity, why? What's the issue with an MN-7?
Limited tuning range
Poor construction
Low quality materials
Kind of like some early MFJ tuners that were used to train new employees with no construction experience and sending them out the door. I don't even think they were actually made by Drake when you take all the quality problems into consideration. Rebadge job or end of a production run just before closing the doors?
I saw a few of the on Ebay about 2 years ago and I was going to bid on a couple of them until I turned up page after page of people saying what a piece of crap those tuners are. I decided not to bid.
If someone thinks I was mislead by bad press then chime in and tell me your story.
I've never met an antenna that the MN-7 couldn't match...but...if you want WARC band coverage or will operate at high power levels, you should be looking at the MN-75 or MN-2700.
The cabinets of all three are identical, save for the '2700 being deeper than the other two. Each has the same basic meter movement. The 200w units have a bandswitch of identical current rating, while the '2700's is higher (naturally).
No one I'm familiar with has even burned any of these tuners up when it has been used at or below its rated power and when a low ( < 1.5:1 ) match could be obtained. You'll damage or destroy one if you try to dissipate the full applied power within its matching circuits so the use of a somewhat resonant antenna is mandated. Of course, the optional 4:1 balun and a ladder-line-fed doublet negates this rule a bit...
W1GUH
07-26-2011, 06:41 PM
But none of them are a BALANCED tuner. Pity...the MN-7 is so pretty & looks so nice next to a TR-7, it would have been a nice looking setup. But....not balanced? Don't want it.
I really have to get back to my tuner project. I have the caps, the roller inductors, a cabinet (from a Ten Tec Jupiter), just need to fabricate a front & back panel. Something else to get to once I plow through some more of the honeydew list.
Done with the clean-up and cosmetic restoration. Next step is to see if they work.
http://i815.photobucket.com/albums/zz79/gyrogeerloose/twinsetal.jpg
KG4CGC
08-01-2011, 04:01 PM
I can think of a couple of Island members that just spooged a little.
I can think of a couple of Island members that just spooged a little.
Nice, but when it comes to Drake spooge the only rigs which really do it for me ar the TR-4130 and R-4245. Missed a set on Ebay last year, and I would have easily gone the $3k they brought...
KG4CGC
08-01-2011, 06:42 PM
I bleed Ten Tec orange.
I bleed Ten Tec orange.
Neither the Orion II nor RX-340 come in that particular color.
w2amr
08-02-2011, 03:47 AM
Done with the clean-up and cosmetic restoration. Next step is to see if they work.
http://i815.photobucket.com/albums/zz79/gyrogeerloose/twinsetal.jpg
Great job, what a nice looking station.
KC2UGV
08-02-2011, 07:06 AM
Done with the clean-up and cosmetic restoration. Next step is to see if they work.
http://i815.photobucket.com/albums/zz79/gyrogeerloose/twinsetal.jpg
Nice work mate :) They look gorgeous!
K7SGJ
08-02-2011, 11:43 AM
They look really nice, Carl. Let me know when they are on the air and I'll give you a shout.
You know, in a pinch they can be used as blocks on your car when you need to change a tire, etc. Safety first!
W1GUH
08-02-2011, 12:51 PM
Limited tuning range
Poor construction
Low quality materials
Kind of like some early MFJ tuners that were used to train new employees with no construction experience and sending them out the door. I don't even think they were actually made by Drake when you take all the quality problems into consideration. Rebadge job or end of a production run just before closing the doors?
I saw a few of the on Ebay about 2 years ago and I was going to bid on a couple of them until I turned up page after page of people saying what a piece of crap those tuners are. I decided not to bid.
If someone thinks I was mislead by bad press then chime in and tell me your story.
But they sell well at hamfests. Mine almost literallly flew out of my arms.
Speaking of tuners, I have to say that I wasn't all that impressed by the MN-4 when I took it apart to clean the switches and such. Not that there's anything particularly wrong with it, just that it's not anything special either. I think my Cubic ST-3B is a far better tuner.
w2amr
08-02-2011, 03:18 PM
I have had my Ten Tec 229 roller inductor tuner for about 23 years. Other that replacing the dial string and cleaning the switch contacts from time to time, it just keeps chugging along.
http://farm4.static.flickr.com/3172/3059779192_c19993f44d.jpg
Brought the R-4A receiver slowly up to power using the variac—it works! No hum from the power supply and I even picked up a local ham using about a foot of #14 wire as an antenna. The dial is a dozen KHz or so out of alignment, but I pretty much expected that. Next step: recapping the HV power supply so I can test the T-4X. That might have to wait until I have a real income, though.
The dial is a dozen KHz or so out of alignment, but I pretty much expected that.
You know that the knob skirt will rotate around the knob, right?
You know that the knob skirt will rotate around the knob, right?
Yeah, I do, but that's just a vernier; it should be on zero whenever a number on the main tuning dial lines up with the cursor. On my receiver, the difference between the freq it's tuned to (determined by using my Icom rig tuned to the same signal) is off by about 25KHz on the main tuning. As I said, I expected that since I had to disassemble the entire thing to clean up the nylon gears, which a previous owner had tried to lubricate—a big no-no on a Drake.
It's entirely a mechanical problem and should not be too hard to fix, I just need to figure out the best way to do it.
http://i111.photobucket.com/albums/n150/Paws264/08/nov-1019.jpg
http://i111.photobucket.com/albums/n150/Paws264/08/Picture009.jpg
http://i111.photobucket.com/albums/n150/Paws264/08/nov-1039.jpg
My second set of twins,
http://i111.photobucket.com/albums/n150/Paws264/late80s.jpg
.My first set of twins (circa 1983)
.
.
My second set of twins
Is that current?
I'm finding the R-4A to be a very nice receiver--sensitive, quiet and much less tiring to listen to for a long time than my Icom.
I think my Cubic ST-3B is a far better tuner.
I have a couple of those, and the commercial variant - the ST-3C.
And two ST-2Bs...an ST-2R. Black, rack-mount version of the 2B. Only 20 were made. When I finish restoring the Cubic Kilowatt I'll rack it all and post pix.
Re: the R4A and quiet RX: Amazing how that works, isn't it? My 751As and R71As appear almost deaf if no antenna is connected, as do the TR-7 and R-7. Other rigs, not so much. The one which really surprised me is the FT-901DM. It's eerily quiet with no antenna attached.
Is that current?
I'm finding the R-4A to be a very nice receiver--sensitive, quiet and much less tiring to listen to for a long time than my Icom.
It was a set that was packaged "Military Style" in a vertical package. They are just a pleasant memory now, after restoring and enjoying them back in 2008-2009, I passed them on to a collector somewhere in OKC.
.
Re: the R4A and quiet RX: Amazing how that works, isn't it? My 751As and R71As appear almost deaf if no antenna is connected, as do the TR-7 and R-7. Other rigs, not so much. The one which really surprised me is the FT-901DM. It's eerily quiet with no antenna attached.
With no antenna connected and the AF gain turned fully clockwise, only a barely audible hiss comes out of a speaker attached to the R-4A. Can't say the same for the Icom.
n2ize
08-11-2011, 08:06 PM
Nice workbench. Wish mine was like that.
W1GUH
08-12-2011, 11:11 AM
With no antenna connected and the AF gain turned fully clockwise, only a barely audible hiss comes out of a speaker attached to the R-4A. Can't say the same for the Icom.
See...you get MORE for your money with the Icom. EVERY ham needs to hear phase noise for hours on end! :evil:
See...you get MORE for your money with the Icom. EVERY ham needs to hear phase noise for hours on end! :evil:
If I pull the coax on my R-71A, IC-751A or IC-745 it's like someone threw the 'mute' switch - there just isn't any.
Other Icoms...not so much.
ETA:
You would also be quite surprised at how well an audio DSP unit cleans up that sort of garbage and makes the radio a little easier to listen to.
Regarding Icoms, Drakes and phases:
http://www.sherweng.com/table.html
The R4C is listed as having an LO noise spacing of 135 dBc/Hz.
An Icom 720A specs at 117 dBc (and it IS noisy).
The Drake R7 and TR7 are listed at 114 and 116 dBc, respectively. But they appear VERY quiet to me...
A Kenwood R-5000 (also considered to be quite noisy by some reviewers) comes in at a whole 6 dBc better than the R7. WTF?
The Icom IC-751 (not the "A" model, which is several dBc quieter) comes in at 127 dBc/Hz.
The R-71A comes in at 128 dBc/Hz.
Many rigs on that list which have historically been highly rated cannot beat those older Icoms, and if one looks at their rated noise floor (R-71A's best: -135 dB with preamp "off") not too many of the competition can equal that figure. Only a handful make it into the < -140dB class...
ka4dpo
09-04-2011, 10:39 PM
Here is an old picture of my shack from about 2004, it the only rig in my shack today is a 756 PRO3 and all the other gear is mothballed in the basement.
I have a Drake B line that I have had for about 25 years now. A while back I built an audio DSP system into and old SP-600 speaker, you can see it on top of the Kenwood.
I mostly use it with my TS-520S but I also connect it to the R4B when things get rough on CW. It works great and is portable so I can use it on other radios. Anyway, the Drake twins are like ham radio gold and should be shined and kept....
W1GUH
09-09-2011, 08:11 AM
I've been good and I've resisted this a long time....but I just can't help myself.
You can keep your Drake twins....these are the twins of choice here...
('Course they'll cost ya much more than all the Drake twins in the world.....)
http://images.askmen.com/galleries/actress/olsen-twins/pictures/olsen-twins-picture-3.jpg
I've been good and I've resisted this a long time....but I just can't help myself.
You can keep your Drake twins....these are the twins of choice here...
('Course they'll cost ya much more than all the Drake twins in the world.....)
http://images.askmen.com/galleries/actress/olsen-twins/pictures/olsen-twins-picture-3.jpg
Needs moar cheeseburger.
KG4CGC
09-09-2011, 10:25 AM
Great work on the rigs. KUDOS!
Okay, got the AC-4 power supply rebuilt and tested then I finally got up the nerve to switch on the T-4X and see what happens. What happens is that it lights up, but I can't get any plate current above idle. The OA2 regulator tube was glowing when I first turned the rig on but after about thirty seconds it stopped and has not come back on since. I'm thinking a bad electrolytic inside the rig itself. There are only a few, including one of those big metal cans, so I think that will be the next step.
Anyone have any advice?
K7SGJ
01-05-2012, 10:24 AM
What's happening to the plate voltage? If you are suspecting a filter, you might do a quick check with the VTVM (or scope) to see how much ac is riding on the dc. It should be pretty low.
w2amr
01-05-2012, 01:16 PM
Okay, got the AC-4 power supply rebuilt and tested then I finally got up the nerve to switch on the T-4X and see what happens. What happens is that it lights up, but I can't get any plate current above idle. The OA2 regulator tube was glowing when I first turned the rig on but after about thirty seconds it stopped and has not come back on since. I'm thinking a bad electrolytic inside the rig itself. There are only a few, including one of those big metal cans, so I think that will be the next step.
Anyone have any advice?I would also check the caps first. Then check the voltages at the VR tube.
Okay, checked out all the non-ceramic caps (there are only five in the whole thing) and found one that was open (zero capacitance):
http://i815.photobucket.com/albums/zz79/gyrogeerloose/cap.jpg
Surprisingly, the big electrolytic can tested fine. Anyhow, there are three caps in there similar to this one and I'm going to change them all out but I'm not sure which type of cap would be the right choice. This doesn't look like an electrolytic to me but that band has got me wondering.
EDIT: Faulty memory, I just discovered that I put the ohmmeter on the wrong cap. It's shorted, not open. That would explain a lot. I'm glad no fuses blew anywhere.
K7SGJ
01-09-2012, 10:44 PM
If the shorted cap is like the yellow one in the photo, an orange drop or mylar should do the trick.
XE1/N5AL
01-09-2012, 11:22 PM
As I recall, some of the non-polar capacitors are marked with a band to indicate which of the two leads is connected to the outside foil after the capacitor is wrapped into a cylinder. It doesn't indicate polarity, since they are polarity insensitive.
In some applications, where one capacitor plate connecs to a low-impedance ground path, you can choose the "banded" outside-foil lead for this side of the connection, and the capacitor will be somewhat self-shielded against RF. In many applications, such as when the capacitor is used for DC blocking, it doesn't matter which end of the capacitor is connected to which side of the circuit.
As I recall, some of the non-polar capacitors are marked with a band to indicate which of the two leads is connected to the outside foil after the capacitor is wrapped into a cylinder. It doesn't indicate polarity, since they are polarity insensitive.
In some applications, where one capacitor plate connecs to a low-impedance ground path, you can choose the "banded" outside-foil lead for this side of the connection, and the capacitor will be somewhat self-shielded against RF. In many applications, such as when the capacitor is used for DC blocking, it doesn't matter which end of the capacitor is connected to which side of the circuit.
Good info, thanks. I've still got a lot to learn about working on boat anchors.
XE1/N5AL
01-10-2012, 12:14 AM
In addition to K7SGJ's suggestion above, an axial-leaded, non-polarized, polyester film capacitor would have a similar form factor to your existing capacitor. CDE Cornell Dubilier, and others, make these.
In addition to K7SGJ's suggestion above, an axial-leaded, non-polarized, polyester film capacitor would have a similar form factor to your existing capacitor. CDE Cornell Dubilier, and others, make these.
Okay, more good info. I really appreciate your help.
kb2crk
01-10-2012, 02:32 AM
Great looking set of twins. I almost bought a set used when I first got my license but the deal I got on my first HW-101 was too good to pass up. Now i just enjoy the green radios...lol
K7SGJ
01-10-2012, 09:16 AM
In addition to K7SGJ's suggestion above, an axial-leaded, non-polarized, polyester film capacitor would have a similar form factor to your existing capacitor. CDE Cornell Dubilier, and others, make these.
I was going to suggest the polyester also, but I know Carl. He would have asked how often it had to be washed and pressed. I just can't bring myself to give him an easy setup like that.
KC2UGV
01-10-2012, 10:20 AM
Good info, thanks. I've still got a lot to learn about working on boat anchors.
You're light years ahead of me, FWIW :)
XE1/N5AL
01-10-2012, 03:53 PM
I was going to suggest the polyester also, but I know Carl. He would have asked how often it had to be washed and pressed. I just can't bring myself to give him an easy setup like that.You guys are just too witty for a dullard like me!
I was going to suggest the polyester also, but I know Carl. He would have asked how often it had to be washed and pressed. I just can't bring myself to give him an easy setup like that.
Are you implying that the white disco suit I've had since 1977 needs to be pressed?
K7SGJ
01-10-2012, 04:49 PM
Are you implying that the white disco suit I've had since 1977 needs to be pressed?
Why yes, I believe it does. But take it off first.
w2amr
01-10-2012, 04:59 PM
Why yes, I believe it does. But take it off first.Anybody have a light? We'll turn him into a disco inferno.
W1GUH
01-12-2012, 08:32 PM
You knew this was coming....
http://www.youtube.com/watch?v=A_sY2rjxq6M
w2amr
01-21-2012, 07:17 AM
You knew this was coming....
http://www.youtube.com/watch?v=A_sY2rjxq6M
It was only a matter of time.
Back on topic, the T-4X is alive!
Finally made the time to check all the voltages, found a component lead that was touching ground where it shouldn't have been, moved it and now it tunes up. Unfortunately, the 6JB6 finals appear to be a bit weak but that's a relatively easy, if not exactly cheap, fix and I've already got a word in to a local guy who sells toobs. Now all I need is a Hi-Z mic with that weird Collins-style plug and I'll be in business.
Okay, the XYL is out of town so I have had some time to play with my radios for a few days. Last night I practiced the tune-up procedure on the T-4X until I had it down. Kind of fun and certainly more satisfying than just switching on the Icom and dialing it to the desired frequency but there's a little problem with the rig. While I can tune it up to 100 watts output on 80 meters, I can only get about 50 watts on 40 meters and correspondingly less power out as I go up in frequency until I hit 10 meters, where maybe 5 watts is the best I can get.
What do you experts think on this? Bad final tubes or is it something in the drive section?
Driver is easiest to replace. Try it first. Then verify that no one has tried "adjusting" the rack assembly which moves the pre-driver/driver tuning slugs in and out of their respective coil cores.
Driver is easiest to replace. Try it first. Then verify that no one has tried "adjusting" the rack assembly which moves the pre-driver/driver tuning slugs in and out of their respective coil cores.
Roger, thanks. I know the tuning slugs are okay (checked them out during the restoration process) so I'll try replacing the 12BY7A driver tube first.
Roger, thanks. I know the tuning slugs are okay (checked them out during the restoration process) so I'll try replacing the 12BY7A driver tube first.
If that fails, suspect the final tubes.
K7SGJ
02-19-2012, 08:52 PM
You might might want to try to neutralize the finals. That could tell you a lot. I'm assuming power dropped as you increased frequency while on a dummy load? How does the drive and plate current act when it's tuned up on the different bands? It's been a very long time since I worked on one of those, so I'm just shooting from the hip. (Maybe I need a hip replacement) Most of the older gear will have a little lower output on 10 then 80 but your Drake seems to have a huge change. Even if the outputs, or driver, tubes were flaky, I wouldn't think there would be such a large difference between 80 and 40, although it's certainly possible. I'd also be curious to see if the drive drops by 50% from 80 to 40. It almost sounds, no offense, that you may not be tuning it up right. I know on some of my older stuff, I can get it to tune in several places with varying degrees of RF output, but there is an optimum sweet spot. The other thing I might be suspicious of, is a fubar cap in the tuning circuit, or maybe a coil that has some debris between a turn or two. That would account for the major output difference vs frequency. Then again, you might just have a bad knob.
No offense taken, but there is really only one tuning that even comes close to working on any given band so I think I got that part right. And yeah, I was turning into a dummy load. The drive control (called Gain on the Drake) needs to be turned progressively farther clockwise to advance the plate current above idle as you move up in frequency; by the time it gets to 10m, it runs up against the stop. Plate current when properly tuned is about what the manual says it should be—between 2800 and 3200 mA.
K7SGJ
02-19-2012, 10:16 PM
Well, if you are getting enough drive to get the plate current in the right neighborhood, that does tend to point to the outputs. Needing to jack the drive way up kinda says "soft tube". Did you try to neutralize them?
Well, if you are getting enough drive to get the plate current in the right neighborhood, that does tend to point to the outputs. Needing to jack the drive way up kinda says "soft tube". Did you try to neutralize them?
No, I haven't. They are the original tubes so I didn't think it necessary but I will look into doing it.
K7SGJ
02-20-2012, 07:06 AM
Keep us posted on the fix. Personally, I always enjoy a success story as I have so few, personally.
I ordered a new set of tubes—a pair of 6JB6 finals and a 12BY7A driver but I'll play with neutralizing the existing tubes before I install them just so I know how to do it.
K7SGJ
02-20-2012, 10:17 AM
Good idea. A lot of folks don't seem to like or want to do that procedure. It sounds more complicated than it really is. They just slap in the tubes and off they go. Besides improving the quality of the signal characteristics, neutralization will also help extend the useful life of the tubes.
Well, I didn't get any serious offers on the Drake twins so I decided that, since it looks as if I'm gonna keep them for a while, I might as well finish up the restoration process. I brought the T-4X over to George, our local boat anchor expert, for some final tweaks and spent a few bucks on a sheet of theatrical lighting gel to replace the faded blue filters on the meter and tuning dial lamps on the R-4A. It looks pretty cool now:
6599
I'll do the same for the transmitter once I get it back.
Anyhow, I had to buy a large sheet of the stuff and only used a few square inches of it so I have a lot left over. If any Islander needs some to restore a Drake 4-line* radio, let me know and I'll send you a piece.
*Might be the same as what they used in the 7-line as well.
W1GUH
07-26-2012, 09:40 PM
Is that current?
I'm finding the R-4A to be a very nice receiver--sensitive, quiet and much less tiring to listen to for a long time than my Icom.
Identical to my reaction to my TR-7 after nothing but synthesized rice boxes for so long. Sooooo nice!!!
W9WLS
07-27-2012, 05:24 AM
There's nothing like the Old Drake & Collins gear to warm up a shack!
I wish you would have said something about the film, Carlo. I have 5 big sheets of it here.
Looks good, by the way!
W1GUH
07-27-2012, 05:21 PM
There's nothing like the Old Drake & Collins gear to warm up a shack!
And one's heart and soul.
BTW, full disclosure: after I replaced the filters, I hooked the receiver up to an antenna, turned it on, waited for it to warm up and...got nothing. All the lights were on but no signal beyond the usual broadband racket I always get here.
"Fuck, what's wrong with this thing?? It was working fine last time I turned it on!"
(Much time spent jiggling knobs and turning switches, checking that all the tube filaments were glowing etc. etc. etc. before giving up because it was time to get ready for work.)
Tried it again this afternoon, with the same results. Sat there in a funk for a while, then a light bulb lit—the crystal/VFO switch on the left side! Sure enough, it had gotten switched to the "Crystal" position, which completely disables the VFO. Flipped it back to the "VFO" position and it's working fine once again.
I also took the time to RTFM again and discovered why the crystal calibrator and noise blanker weren't working. Fixed that problem with a shorted RCA plug in the "Muting" jack on the back panel.
Well, I always do learn better via empirical methods...
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