Re: RV-75 from Hamvention
Success! A few new caps and cleaning the grounds seems to have fixed it. Very stable! I only did the caps on the top board as I didn't have the 10 & 100uf for the bottom board. I will pick some up tomorrow and this should be back online. Thanks Evan for your thoughts on this thing!
73,? Eric? K8cca? 
Hey guys,
Picked up a nice looking Drake RV-75 vfo for my TR-7 last weekend. Hooked it up last night and my main vfo was in the middle of the 20m band, but when I switched on the remote vfo freq drop to around 13.9mhz and I am not able to adjust it. I guess I got a hamfest special. Any hints on what to look for? I have not even opened it up. Got a great deal on it however so I hope I can fix it. I showed it to Evan, K9SQG when I ran into him there.?
Thanks in advance,? Eric? K8cca?
|
Re: RV-75 from Hamvention
Success! A few new caps and cleaning the grounds seems to have fixed it. Very stable! I only did the caps on the top board as I didn't have the 10 & 100uf for the bottom board. I will pick some up tomorrow and this should be back online. Thanks Evan for your thoughts on this thing!
73,? Eric? K8cca? 
Hey guys,
Picked up a nice looking Drake RV-75 vfo for my TR-7 last weekend. Hooked it up last night and my main vfo was in the middle of the 20m band, but when I switched on the remote vfo freq drop to around 13.9mhz and I am not able to adjust it. I guess I got a hamfest special. Any hints on what to look for? I have not even opened it up. Got a great deal on it however so I hope I can fix it. I showed it to Evan, K9SQG when I ran into him there.?
Thanks in advance,? Eric? K8cca?
|
Re: The Drake 2B and its Frequency Spread Limitations
My first 1-A came with diodes replacing the 6X4,? At the time, it was an easy mod that was popular at a time when people wanted to replace tubes.? I removed the diodes and bought a NOS 6X4 off eBay for about $4 + shipping.
If not properly compensated, using solid state diodes in place? of a tube can raise the voltage on the plate supply.? In the case of the 1-A, Drake used lots of taps to provide various voltages instead of just perhaps using two different plate voltages like the R-4(any).? The highest voltages were near 200V before I put the tube back in.
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Tuesday, May 20th, 2025 at 6:32 PM, Richard W2ONE via groups.io <cowboyhat@...> wrote:
Hey Gary,
?
Here are some more pictures of my cabinet.? Yes, a previous owner stuck a Heathkit 100 kc Calibrator in place of the Drake 100 kc Calibrator.? A previous owner also replaced the 6X4 tube with two diodes.? I believe I read somewhere that this is a hack on the 2B, but I do not remember if the hack was an improvement over the use of the 6X4 tube or as a substitute if the tube cannot be located.? I would appreciate any words of wisdom that anyone has on these two situations (my Heathkit calibrator and the diode replacement of the 6X4 tube).
?
Other pictures showing the crystals that have been installed and the bottom of the chasis.
?
Richard
W2ONE
?
?
?
?
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Re: OT: Looking for help with Kenwood Handheld
I think I remember that Mouser and/or Digikey can weld on tabs for any of their batteries for you.
73, Gary WB6OGD
Nice!? I wasn't aware of their site.? I've gotten in touch with them regarding a CR1220 with tabs.
Thanks!
Barry - N4BUQ
Take a look at Batteries America (). They can probably supply what you need.?
Tony - W9JXN? This is the only amateur radio group of which I'm a member so I'm looking for a bit of help.? Is there an appropriate group for older Kenwood hand-helds?
I have a TH-28A that needs an internal lithium battery and am having no luck finding a suitable replacement.? If someone can point me to a group or, even better, point me to a source for those batteries, I would appreciate it.
Note that I can find all sorts of lithium coin cells with solder tabs but none of the ones I find match the configuration of the one in my TH-28A.
Thanks,
Barry - N4BUQ
|
Re: Drake 2B Instruction Book
Richard,
Your 2B looks in good condition, good buy.
A Heathkit calibrator is a good substiute for the Drake.? The only thing I would do is make some kind of bracket
to mount it down.? If those wires on its socket touch ground (or your hand!) damage can be done.
?
Diodes should work fine for a tube replacement.? I would have soldered them in myself but if they are making
good connection in the socket and don't fall loose, that should be ok.
?
So, how do we fix it?
You should be able to hear the calibrator signal every 100KHz? (KC as we used to say, hi hi).
There is a CAL switch on the front to turn it on.? You need to set the band and peak the preselector to hear it.
If you don't hear it, try all the bands, its possible the band switch or a band crystal is bad.
80meters is where I would start, it doesn't need a band crystal.
?
If you dont' hear it...
Remove each tube one at a time.? Make sure its the right tube.
Insert and reset each tube several times to clean its pins.? I would do all this first before I powered it up.
Also, work the bandswitch multiple times.
?
Oh FIRST THING.? Check the fuse, it should be 0.6Amp? (600ma) slow blow.? I have seen 6AMP fuses in radios,
that would not protect anything and would insure that if anything goes wrong you WILL have damage.
?
73,
Gary
WB6OGD
|
Drake 2B Instruction Book
?
I found the Drake 2B Instruction Book on line, but it is a digital copy made after several generations of machine copies - it is not very clear in some places.? A couple of the pages are also out of order.? I have found a different digital version that is cleaner and has a few additional pages of information.? Interestingly, this other version also has a slightly different description of the crystals and how to use them - probably a version made that was before or after the version now on line.
?
I am attaching this cleaner version here to share.
?
Richard
W2ONE
|
Re: The Drake 2B and its Frequency Spread Limitations
Hey Gary,
?
Here are some more pictures of my cabinet.? Yes, a previous owner stuck a Heathkit 100 kc Calibrator in place of the Drake 100 kc Calibrator.? A previous owner also replaced the 6X4 tube with two diodes.? I believe I read somewhere that this is a hack on the 2B, but I do not remember if the hack was an improvement over the use of the 6X4 tube or as a substitute if the tube cannot be located.? I would appreciate any words of wisdom that anyone has on these two situations (my Heathkit calibrator and the diode replacement of the 6X4 tube).
?
Other pictures showing the crystals that have been installed and the bottom of the chasis.
?
Richard
W2ONE
?
?
?
?
|
Re: OT: Looking for help with Kenwood Handheld
I have one that I bought from a guy in Germany.
It has a controller that lets you specify the amount of energy in joules
that you put into the weld. I use it with a car battery.
- Jerry, KF6VB
|
Re: "I THE cantenna unveiled!
?
In addition to the lesser concerns already expressed here, I would point out that PCB dielectric oil is quite dangerous if it burns.? The poison known as dioxin is produced.?? No one wants a lung-full of that in the case of a fire.
?
?
/??
--------------------------------------------------------------------??
Radio is your best entertainment value.??
--------------------------------------------------------------------??
?
?
?
?
|
Re: OT: Looking for help with Kenwood Handheld
toggle quoted message
Show quoted text
On May 20, 2025, at 3:58?PM, n4buq via groups.io <n4buq@...> wrote:
? Nice!? I wasn't aware of their site.? I've gotten in touch with them regarding a CR1220 with tabs.
Thanks!
Barry - N4BUQ
Take a look at Batteries America (). They can probably supply what you need.?
Tony - W9JXN? On May 20, 2025, at 9:26?AM, n4buq via groups.io <n4buq@...> wrote:
This is the only amateur radio group of which I'm a member so I'm looking for a bit of help. ?Is there an appropriate group for older Kenwood hand-helds?
I have a TH-28A that needs an internal lithium battery and am having no luck finding a suitable replacement. ?If someone can point me to a group or, even better, point me to a source for those batteries, I would appreciate it.
Note that I can find all sorts of lithium coin cells with solder tabs but none of the ones I find match the configuration of the one in my TH-28A.
Thanks,
Barry - N4BUQ
|
Re: OT: Looking for help with Kenwood Handheld
Nice!? I wasn't aware of their site.? I've gotten in touch with them regarding a CR1220 with tabs.
Thanks!
Barry - N4BUQ
Take a look at Batteries America (). They can probably supply what you need.?
Tony - W9JXN? On May 20, 2025, at 9:26?AM, n4buq via groups.io <n4buq@...> wrote:
This is the only amateur radio group of which I'm a member so I'm looking for a bit of help. ?Is there an appropriate group for older Kenwood hand-helds?
I have a TH-28A that needs an internal lithium battery and am having no luck finding a suitable replacement. ?If someone can point me to a group or, even better, point me to a source for those batteries, I would appreciate it.
Note that I can find all sorts of lithium coin cells with solder tabs but none of the ones I find match the configuration of the one in my TH-28A.
Thanks,
Barry - N4BUQ
|
Re: OT: Looking for help with Kenwood Handheld
I didn't know such a thing was being made.? Nice to know.? Hopefully it won't come to that and I can get a battery with tabs that will work (and I think I see some being offered).
Thanks, Barry - N4BUQ
Spot-weld the tabs yourself: AMAZON - Docreate Hand-Held Spot Welder, 5.5KW, $30 73 de Andrew/N5ASE
I didn't know that could be done as a service like that.? We have a Batteries Plus but not sure if they'd do that. Thanks for the tip! Barry - N4BUQ If you have a Batteries-Plus, or Batteries & Bulbs store near you, they might have one. They have the ability to spot-weld tabs on about any battery.
This is the only amateur radio group of which I'm a member so I'm looking for a bit of help.? Is there an appropriate group for older Kenwood hand-helds?
I have a TH-28A that needs an internal lithium battery and am having no luck finding a suitable replacement.? If someone can point me to a group or, even better, point me to a source for those batteries, I would appreciate it.
Note that I can find all sorts of lithium coin cells with solder tabs but none of the ones I find match the configuration of the one in my TH-28A.
Thanks,
Barry - N4BUQ
|
Re: OT: Looking for help with Kenwood Handheld
?Take a look at Batteries America (). They can probably supply what you need.?
Tony - W9JXN?
toggle quoted message
Show quoted text
On May 20, 2025, at 9:26?AM, n4buq via groups.io <n4buq@...> wrote:
?This is the only amateur radio group of which I'm a member so I'm looking for a bit of help. ?Is there an appropriate group for older Kenwood hand-helds?
I have a TH-28A that needs an internal lithium battery and am having no luck finding a suitable replacement. ?If someone can point me to a group or, even better, point me to a source for those batteries, I would appreciate it.
Note that I can find all sorts of lithium coin cells with solder tabs but none of the ones I find match the configuration of the one in my TH-28A.
Thanks,
Barry - N4BUQ
|
Hey guys,
Picked up a nice looking Drake RV-75 vfo for my TR-7 last weekend. Hooked it up last night and my main vfo was in the middle of the 20m band, but when I switched on the remote vfo freq drop to around 13.9mhz and I am not able to adjust it. I guess I got a hamfest special. Any hints on what to look for? I have not even opened it up. Got a great deal on it however so I hope I can fix it. I showed it to Evan, K9SQG when I ran into him there.?
Thanks in advance,? Eric? K8cca?
|
Re: OT: Looking for help with Kenwood Handheld
Spot-weld the tabs yourself:
AMAZON - Docreate Hand-Held Spot Welder, 5.5KW, $30
73 de Andrew/N5ASE
I didn't know that could be done as a service like that.? We have a Batteries Plus but not sure if they'd do that.
Thanks for the tip! Barry - N4BUQ
If you have a Batteries-Plus, or Batteries & Bulbs store near you, they might have one. They have the ability to spot-weld tabs on about any battery.
This is the only amateur radio group of which I'm a member so I'm looking for a bit of help.? Is there an appropriate group for older Kenwood hand-helds?
I have a TH-28A that needs an internal lithium battery and am having no luck finding a suitable replacement.? If someone can point me to a group or, even better, point me to a source for those batteries, I would appreciate it.
Note that I can find all sorts of lithium coin cells with solder tabs but none of the ones I find match the configuration of the one in my TH-28A.
Thanks,
Barry - N4BUQ
|
Re: OT: Looking for help with Kenwood Handheld
Yes - It is a 12mm (maybe 12.5mm) battery. From what I'm seeing, the solder tabs on those are much more in line with the ones on my battery.
Thanks so much for setting me straight on that!
Barry - N4BUQ
toggle quoted message
Show quoted text
Yeah, I need to measure it.
Thanks,
Barry - N4BUQ
GA, CR2032 seems to me is somewhat big, perhaps a CR1220 type fits better.
Regards
Guillermo - LU5WE.
El 20/5/25 a las 14:57, n4buq escribió:
I've seen some of those but most of them have rather larger and wider-
spaced solder tabs.? I'm attaching a picture of what's in my radio.? I
might be able to trim the tabs as it appears that may have been what was
done to these from the factory.? I'm pretty sure it's a CR-2032 but the
part number in the service manual doesn't show up anywhere I've looked.
Thanks,
Barry - N4BUQ
I found one for my FT-470 on Amazon. Gamers have lots of devices
with these sorts of batteries.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail <> for iOS
On Tue, May 20, 2025 at 10:26, n4buq <n4buq@...
<mailto:On%20Tue,%20May%2020,%202025%20at%2010:26,
%20n4buq%20<<a%20href=>> wrote:
This is the only amateur radio group of which I'm a member so
I'm looking for a bit of help. Is there an appropriate group for
older Kenwood hand-helds?
I have a TH-28A that needs an internal lithium battery and am
having no luck finding a suitable replacement. If someone can
point me to a group or, even better, point me to a source for
those batteries, I would appreciate it.
Note that I can find all sorts of lithium coin cells with solder
tabs but none of the ones I find match the configuration of the
one in my TH-28A.
Thanks,
Barry - N4BUQ
|
Re: OT: Looking for help with Kenwood Handheld
Yeah, I need to measure it.
Thanks,
Barry - N4BUQ
toggle quoted message
Show quoted text
GA, CR2032 seems to me is somewhat big, perhaps a CR1220 type fits better.
Regards
Guillermo - LU5WE.
El 20/5/25 a las 14:57, n4buq escribió:
I've seen some of those but most of them have rather larger and wider-
spaced solder tabs.? I'm attaching a picture of what's in my radio.? I
might be able to trim the tabs as it appears that may have been what was
done to these from the factory.? I'm pretty sure it's a CR-2032 but the
part number in the service manual doesn't show up anywhere I've looked.
Thanks,
Barry - N4BUQ
I found one for my FT-470 on Amazon. Gamers have lots of devices
with these sorts of batteries.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail <> for iOS
On Tue, May 20, 2025 at 10:26, n4buq <n4buq@...
<mailto:On%20Tue,%20May%2020,%202025%20at%2010:26,
%20n4buq%20<<a%20href=>> wrote:
This is the only amateur radio group of which I'm a member so
I'm looking for a bit of help. Is there an appropriate group for
older Kenwood hand-helds?
I have a TH-28A that needs an internal lithium battery and am
having no luck finding a suitable replacement. If someone can
point me to a group or, even better, point me to a source for
those batteries, I would appreciate it.
Note that I can find all sorts of lithium coin cells with solder
tabs but none of the ones I find match the configuration of the
one in my TH-28A.
Thanks,
Barry - N4BUQ
|
Re: OT: Looking for help with Kenwood Handheld
GA, CR2032 seems to me is somewhat big, perhaps a CR1220 type fits better.
Regards
Guillermo - LU5WE.
toggle quoted message
Show quoted text
El 20/5/25 a las 14:57, n4buq escribió: I've seen some of those but most of them have rather larger and wider- spaced solder tabs.? I'm attaching a picture of what's in my radio.? I might be able to trim the tabs as it appears that may have been what was done to these from the factory.? I'm pretty sure it's a CR-2032 but the part number in the service manual doesn't show up anywhere I've looked.
Thanks,
Barry - N4BUQ
I found one for my FT-470 on Amazon. Gamers have lots of devices
with these sorts of batteries.
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail <> for iOS
On Tue, May 20, 2025 at 10:26, n4buq <n4buq@...
<mailto:On%20Tue,%20May%2020,%202025%20at%2010:26,
%20n4buq%20<<a%20href=>> wrote:
This is the only amateur radio group of which I'm a member so
I'm looking for a bit of help. Is there an appropriate group for
older Kenwood hand-helds?
I have a TH-28A that needs an internal lithium battery and am
having no luck finding a suitable replacement. If someone can
point me to a group or, even better, point me to a source for
those batteries, I would appreciate it.
Note that I can find all sorts of lithium coin cells with solder
tabs but none of the ones I find match the configuration of the
one in my TH-28A.
Thanks,
Barry - N4BUQ
|
Re: OT: Looking for help with Kenwood Handheld
Barry,
If your TH-28A is anything like the Realistic/Radio Shack HTX-202 and HTX-404 HTs, I replaced the internal tabbed 3 volt Lithium cell used in these rigs with a popular CR2032 coin cell and accompanying holder. So now the next time it needs replacement, I can just pop out the old one and insert a new one. No more soldering required. And those CR2032 coin cells are used EVERYWHERE these days.
73 de John, KD2BD
|
Re: OT: Looking for help with Kenwood Handheld
I didn't know that could be done as a service like that.? We have a Batteries Plus but not sure if they'd do that.
Thanks for the tip! Barry - N4BUQ
If you have a Batteries-Plus, or Batteries & Bulbs store near you, they might have one. They have the ability to spot-weld tabs on about any battery.
This is the only amateur radio group of which I'm a member so I'm looking for a bit of help.? Is there an appropriate group for older Kenwood hand-helds?
I have a TH-28A that needs an internal lithium battery and am having no luck finding a suitable replacement.? If someone can point me to a group or, even better, point me to a source for those batteries, I would appreciate it.
Note that I can find all sorts of lithium coin cells with solder tabs but none of the ones I find match the configuration of the one in my TH-28A.
Thanks,
Barry - N4BUQ
|
K8CCA
Gary WB6OGD