The radio has good RF white noise at the speaker for now, perhaps after changing the bad tube it will work.

There is one tube that I cannot identify to test, there is no marking on the glass but the label on the chassis identifies it as a RT150. Anyone have any idea as to what this tube is? Perhaps a ballast tube?

Thank you,

Mitch

Could that be RT510? This is a ballast tube (3TF7) in series with V505 & V701, VFO & BFO oscillators. If these tubes light the ballast is ok.

Norm

:I have tested all of the tubes in the radio and found one bad one. It is a 6AK5 that subbed for a 5654, dead in my tester.
:
:The radio has good RF white noise at the speaker for now, perhaps after changing the bad tube it will work.
:
:There is one tube that I cannot identify to test, there is no marking on the glass but the label on the chassis identifies it as a RT150. Anyone have any idea as to what this tube is? Perhaps a ballast tube?
:
:Thank you,
:
:Mitch
:

Yes, after cleaning my glasses it is a RT510. I will power the radio up tomorrow to see if the V505 & V701 light up. I will post the results.

Both tubes tested good on my tube tester.

Nice to know that on this site there is so much knowledge, may need some help on this radio as I have never seen anything like it in my life.
:
::I have tested all of the tubes in the radio and found one bad one. It is a 6AK5 that subbed for a 5654, dead in my tester.
::
::The radio has good RF white noise at the speaker for now, perhaps after changing the bad tube it will work.
::
::There is one tube that I cannot identify to test, there is no marking on the glass but the label on the chassis identifies it as a RT150. Anyone have any idea as to what this tube is? Perhaps a ballast tube?
::
::Thank you,
::
::Mitch
::
:
:

Mitch

Yes you can test the ballast with an ohm meter. The best test is to see it tubes V505 and V701 light.

Pin #2 and #3 are connected together. Pin #7 and #8 are connected together. There should be resistance between pin #3 and #7.

As far as I'm concerned R390A is the worlds best receiver.

Norm

:::Mitch
:::
::: Could that be RT510? This is a ballast tube (3TF7) in series with V505 & V701, VFO & BFO oscillators. If these tubes light the ballast is ok.
:::
:::Norm
:::
:::Hello Norm,
::
::Yes, after cleaning my glasses it is a RT510. I will power the radio up tomorrow to see if the V505 & V701 light up. I will post the results.
::
::Both tubes tested good on my tube tester.
::
::Nice to know that on this site there is so much knowledge, may need some help on this radio as I have never seen anything like it in my life.
:::
::::I have tested all of the tubes in the radio and found one bad one. It is a 6AK5 that subbed for a 5654, dead in my tester.
::::
::::The radio has good RF white noise at the speaker for now, perhaps after changing the bad tube it will work.
::::
::::There is one tube that I cannot identify to test, there is no marking on the glass but the label on the chassis identifies it as a RT150. Anyone have any idea as to what this tube is? Perhaps a ballast tube?
::::
::::Thank you,
::::
::::Mitch
::::
:::
:::
::
::
:Is there a pin out of the ballast tube anywhere, can I test this tube out of the circuit with a ohm meter?
:
:Mitch
:

An update on this radio. First though, the gentleman that brought the radio to my shop with his wife is in his eighties, he is an ex Navy-radio operator/ET. He is blind. In his blindness he designs and sells high power antenna transmitter and receiver towers. Beyond me.

When he brought me the radio he ran his hand across the face of the radio and explained all of the functions of the switches and controls, still beyond me. He gave me the book/manual for the radio and even sited some pages for me to look at for some repairs.

When I got the radio it was dead as to station reception, still is, but good RF noise on all bands.

Now, the RT510 is open, I did the ohm resistor test and it is open between pins 3 & 7.

Also, the filaments of the V505 & V701 do not light up. They do test good in my tube tester.

I do not want to try the work around that I have found on the web for this issue, rather a replacement ballast tube. The original is a RT510, what is the best exact replacement?

I have also found a bad 6AK5 and O2A tube, maybe the radio will work with these weak tubes, I will change these (buy) tubes as I want him to be able to listen to the radio without another failure in his lifetime.

A source for the tubes would be appreciated, especially the ballast tube.

Testing 26 tubes is quit a job, and keep the record straight, retest when your mind is foggy, drink coffee.

Thank you,

Mitch

Also, check the 0A2 again. They are easy to test wrong.
The RT510, as I recall you mentioned, that the RT510 feeds the filament voltage to the BFO circuitry. The BFO is only necessary for the reception of Morse code or single side band voice. If the owner does not listen to these he does not need the BFO. This RT510 may have been open for years while he was listening to it and he didn't know it.
The schematic will tell the tale of how important this is.

All the Best,

Bill Grimm

I spoke with the radio owner and told him that I found one tube that did not meet emissions tests on my tube tester (6AK5) and the 0A2 read at a scale of 2 instead of at least 10 as a regulator.

The RT510 was open, it provides the filament source for the V505 and V701 tubes. Both of these tubes do test good on my tube tester, in the radio though there is no filament voltage to them. (RT510 open).

He told me to purchase both tubes (under $10.00) I also found a 3TF7 ballast, very expensive. He did not want any work around with a high watt resistor.

He listens to the radio every night, not now but.

I will replace the tubes and ballast later this week when they arrive. I will probably need some help if the radio does not receive stations at that time.

The 6AK5 tested almost completely dead, 9% emissions as opposed to other 6AK5's tested at 80%.

My concern is to make sure that I don't return the radio working and it fails in a week or two.

All comments and support are welcome to help me, I am not sure that I know how to operate this radio correctly, if I get stations in it will surprise to no end.

Thank you for the help,

Mitch

https://www.fairradio.com/catalog.php?mode=search&keywords=3TF7&submit.x=13&submit.y=8

Clifton

::::Mitch
::::
:::: Yes you can test the ballast with an ohm meter. The best test is to see it tubes V505 and V701 light.
::::
:::: Pin #2 and #3 are connected together. Pin #7 and #8 are connected together. There should be resistance between pin #3 and #7.
::::
:::: As far as I'm concerned R390A is the worlds best receiver.
::::
::::Norm
::::
:::::::Mitch
:::::::
::::::: Could that be RT510? This is a ballast tube (3TF7) in series with V505 & V701, VFO & BFO oscillators. If these tubes light the ballast is ok.
:::::::
:::::::Norm
:::::::
:::::::Hello Norm,
::::::
::::::Yes, after cleaning my glasses it is a RT510. I will power the radio up tomorrow to see if the V505 & V701 light up. I will post the results.
::::::
::::::Both tubes tested good on my tube tester.
::::::
::::::Nice to know that on this site there is so much knowledge, may need some help on this radio as I have never seen anything like it in my life.
:::::::
::::::::I have tested all of the tubes in the radio and found one bad one. It is a 6AK5 that subbed for a 5654, dead in my tester.
::::::::
::::::::The radio has good RF white noise at the speaker for now, perhaps after changing the bad tube it will work.
::::::::
::::::::There is one tube that I cannot identify to test, there is no marking on the glass but the label on the chassis identifies it as a RT150. Anyone have any idea as to what this tube is? Perhaps a ballast tube?
::::::::
::::::::Thank you,
::::::::
::::::::Mitch
::::::::
:::::::
:::::::
::::::
::::::
:::::Is there a pin out of the ballast tube anywhere, can I test this tube out of the circuit with a ohm meter?
:::::
:::::Mitch
:::::
::::
::::
:::Hello gentlemen again,
:::
:::An update on this radio. First though, the gentleman that brought the radio to my shop with his wife is in his eighties, he is an ex Navy-radio operator/ET. He is blind. In his blindness he designs and sells high power antenna transmitter and receiver towers. Beyond me.
:::
:::When he brought me the radio he ran his hand across the face of the radio and explained all of the functions of the switches and controls, still beyond me. He gave me the book/manual for the radio and even sited some pages for me to look at for some repairs.
:::
:::When I got the radio it was dead as to station reception, still is, but good RF noise on all bands.
:::
:::
:::Now, the RT510 is open, I did the ohm resistor test and it is open between pins 3 & 7.
:::
:::Also, the filaments of the V505 & V701 do not light up. They do test good in my tube tester.
:::
:::I do not want to try the work around that I have found on the web for this issue, rather a replacement ballast tube. The original is a RT510, what is the best exact replacement?
:::
:::I have also found a bad 6AK5 and O2A tube, maybe the radio will work with these weak tubes, I will change these (buy) tubes as I want him to be able to listen to the radio without another failure in his lifetime.
:::
:::A source for the tubes would be appreciated, especially the ballast tube.
:::
:::Testing 26 tubes is quit a job, and keep the record straight, retest when your mind is foggy, drink coffee.
:::
:::Thank you,
:::
:::Mitch
:::
::Hi Mitch,
:: Interesting story. Seems like this R-390 is one of the old guy's better friends. Let's see if we can get her going.
:: One thing that strikes me is that it has three bad tubes. I suspect that it is just one of the tubes that took the radio down.
:: Murphy's law would say that the RT510 is the one, as finding a new one would be a big task.
:: I don't think Murphy had his way this time, though. My money is on the 6AK5. It is an IF tube and its failure would cause the kind of problem you are seeing.
:: Replacements for the 0A2 are also readily available.
:: Some sources are:
:: 1. http://www.tubesandmore.com/
:: 2. http://www.oldradioparts.com/
:: 3. http://www.vacuumtubes.net/
:: 4. http://www.radiodaze.com/
:: 5. eBay, of course. They have two categories for tubes, no RT510, though.
::
:: Also, check the 0A2 again. They are easy to test wrong.
:: The RT510, as I recall you mentioned, that the RT510 feeds the filament voltage to the BFO circuitry. The BFO is only necessary for the reception of Morse code or single side band voice. If the owner does not listen to these he does not need the BFO. This RT510 may have been open for years while he was listening to it and he didn't know it.
:: The schematic will tell the tale of how important this is.
::
::All the Best,
::
::Bill Grimm
::
:Hello Bill,
:
:I spoke with the radio owner and told him that I found one tube that did not meet emissions tests on my tube tester (6AK5) and the 0A2 read at a scale of 2 instead of at least 10 as a regulator.
:
:The RT510 was open, it provides the filament source for the V505 and V701 tubes. Both of these tubes do test good on my tube tester, in the radio though there is no filament voltage to them. (RT510 open).
:
:He told me to purchase both tubes (under $10.00) I also found a 3TF7 ballast, very expensive. He did not want any work around with a high watt resistor.
:
:He listens to the radio every night, not now but.
:
:I will replace the tubes and ballast later this week when they arrive. I will probably need some help if the radio does not receive stations at that time.
:
:The 6AK5 tested almost completely dead, 9% emissions as opposed to other 6AK5's tested at 80%.
:
:My concern is to make sure that I don't return the radio working and it fails in a week or two.
:
:All comments and support are welcome to help me, I am not sure that I know how to operate this radio correctly, if I get stations in it will surprise to no end.
:
:Thank you for the help,
:
:Mitch
:
:
:
:

I found one at this site for $37.50 + $7.00 shipping. They have 14 in stock.

http://www.vacuumtubesinc.com/Default.aspx

Mitch

I have an experiment you may want to try. As I recall one of the tubes that isn't lighting due to the open ballast tube is a good 6AK5. Try putting it in the place of the 6AK5 you found to be bad.
You may get a happy surprise.

In any case let me know when the tubes arrive.

All the Best,

Bill

There is only one other 6AK5 in the radio, re 5654, it is V401.

I have not found its (5654 V401) purpose yet. I will try to change them out with each other and see what the results are.

I had a new 0A2 in my tube collection and have changed it out already. I will post if the tube change helps. Else I will wait for the new 6AK5 and the 3TF7.

Thank you for staying on this radio with me,

Mitch

If anyone is familiar with this radio, can you post the switch and control positions I need to be in to tune in the BC band? (KC MC)

I might get the tubes I need tomorrow and hate trying to operate blind, I do not know how to operate this radio.

Thank you,

Mitch

I installed a new 3TF7 tonight, the V505 and V701 filaments lit. The Beat Frequency Oscillator is working and the Variable Frequency Oscillator is working.

The radio does produce good RF noise that seems to be internal to the radio, not from the antenna. The 6AK5 is on its way and I am hopeful that this will produce reception from the radio, if not I will surely need some help here.

Comments appreciated.

Mitch

Sir Mitch . . . . . W e l l l l l l l . . . .What did you think of that litle puppy when you first saw it ? With its 25 or so tube / bun warmer complement . . . along with its WEIGHT ? That unit, along with a companion Collins xmitter was mounted on my jeeps rear, while onverseas in Laos,VN and Thailand. And then, when back Conus, I was notified of a MARS station closing down with their racks of units, and was able to get one on a hand receipt for its use for several years. The depicted settings below, should fill your request, with the variables being red lined, along with the presence of a 840 Khz station being receivable in your locale. 73's de Edd Gas prices aren't really that bad when you consider that you're essentially buying some huge, badass dinosaurs in their liquid form.

::::Hi Mitch,
:::: My money is still on the bad 6AK5.
:::: Having a good 0A2 helps.
:::: One thing you have going for you is that this isn't a radio that has been sitting around dead in a radio shop because the owner found it too challenging to fix commercially in its day.
:::: Instead you have a radio that may have been working well until recently. You are doing a repair, not a restoration.
::::
:::: I have an experiment you may want to try. As I recall one of the tubes that isn't lighting due to the open ballast tube is a good 6AK5. Try putting it in the place of the 6AK5 you found to be bad.
:::: You may get a happy surprise.
::::
:::: In any case let me know when the tubes arrive.
::::
::::All the Best,
::::
::::Bill
::::
:::Hello Bill,
:::
:::There is only one other 6AK5 in the radio, re 5654, it is V401.
:::
:::I have not found its (5654 V401) purpose yet. I will try to change them out with each other and see what the results are.
:::
:::I had a new 0A2 in my tube collection and have changed it out already. I will post if the tube change helps. Else I will wait for the new 6AK5 and the 3TF7.
:::
:::Thank you for staying on this radio with me,
:::
:::Mitch
:::
::Hello,
::
::If anyone is familiar with this radio, can you post the switch and control positions I need to be in to tune in the BC band? (KC MC)
::
::I might get the tubes I need tomorrow and hate trying to operate blind, I do not know how to operate this radio.
::
::Thank you,
::
::Mitch
::
:Hello,
:
:I installed a new 3TF7 tonight, the V505 and V701 filaments lit. The Beat Frequency Oscillator is working and the Variable Frequency Oscillator is working.
:
:The radio does produce good RF noise that seems to be internal to the radio, not from the antenna. The 6AK5 is on its way and I am hopeful that this will produce reception from the radio, if not I will surely need some help here.
:
:Comments appreciated.
:
:Mitch
:

Sir Mitch You are already set up for shortwave, just confirm that your antenna wire is going into the left WHIP ANTENNA BNC fitting or just insert the bare wirae into that center pin within the BNC fitting. Then check for the few VOA stations left, or for our WWV time signal beacons at 2.5-10-15-25 mhz. The most of the foreign stations will be found clustered on the 16-19-22-25-31-41-49 meter bands. Use my references below to convert those bands to Mhz and the last ref is particularly useful for look up or identify. If you want to shoot for Ham SSB transmissions, save me some keystrokes and use the R-390-URR BIBLE that I have already sent to you. 73's de Edd You do not need a parachute to skydive. You only need a parachute to skydive TWICE.

> > > SW Frequencies 1< < <

> > > SW Frequencies 2 < < <

> > > SW Frequencies/Stations Look-up< < <

.

::::Hi Mitch,
:::: Didn't Edd do a bang up job on the settings? The turning the mouse point to a fly was a nice touch!
::::
:::: My money is still on the 6AK5. If you have an antenna on this you won't need to crank it very far before getting a signal.
:::: Be sure you can turn the BFO off. I expect the owner doesn't use it.
::::
::::Best Regards,
::::
::::Bill Grimm
::::
:::To all again,
:::
:::While I am waiting for the last tube I do need to replace the dial lamps, I measured wrong the other day and there is 6.3 VAC at the bulbs, they are burned out.
:::
:::They are GE 328's.
:::
:::See Photo.
:::
:::Can anyone direct me to where to find these bulbs?
:::
:::Mitch
:::
:::
:::
::Try 1000bulbs:
::http://www.1000bulbs.com/search/?q=328
:: You can get a 12 pack for $2.55.
:: I replaced many of these when I was in the service.
::
::All the Best,
::
::Bill
::
:Hello everyone,
:
:The receiver is working.
:
:If anyone knows Bill G. and you are in Vegas copy every bet he makes, well Bill when I changed the 6AK5 the radio came alive on the AM band. I am listening to some AM stations tonight.
:
:Edd helped with the settings for the AM band, I haven't a clue as to the SW band settings.
:
:I would assume that if the AM is working and I am receiving stations that the SW is also working.
:
:So, how do I go about setting the radio up to receive the SW bands? SW may be difficult for me to receive here although I have received a few stations in the past.
:
:I do have a 20 foot wire antenna connected to the radio.
:
:My appreciation to all that have helped me on this receiver.
:
:Mitch
: