Forums :: NEW! Web Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently Jan Sat 16, 2021 1:44 am


All times are UTC [ DST ]





Post New Topic Post Reply  [ 41 posts ]  Go to page 1, 2, 3  Next
Author Message
 Post subject: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 2:08 am 
Member
User avatar

Joined: Jul Fri 21, 2017 9:58 pm
Posts: 1428
Location: Erie, Pa.
I am seeing that if a Collins receiver is unobtainable, the Hammarland Super Pro series come close in most respects, even having a slight edge for some top of the line models.

But someone pointed out there are National general coverage models of similar quality that have much better audio to boot, at a much more palatable price.

If you had your druthers between the two, which and why?

I have checked out most of the Hammarlands, but don't know what National models are the stars of the lineup.

The early HRO's have a cool history and are reputedly able to clearly receive a minus S1 signal with a decent antenna, but aren't designed for sideband.

I thought asking here might save me a few hours of googling.

_________________
Tim, N3YQV
"I'm SHOCKED! SHOCKED, I tell you!"


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 2:35 am 
Member

Joined: Jan Tue 07, 2020 1:41 am
Posts: 3567
Location: Fenton, MI 48430
I read you want general coverage. It is best to know your budget as prices vary a lot. A very good receiver with great audio having push-pull audio output is the National NC-183D. The 183D is dual conversion thus has no images on shortwave. The NC-183 is not dual conversion. I find the NC-183D for $250-$350. A deal may be had on the QTH.com site with a wanted ad.

However, you want a SSB receiver? Most tube receivers are not designed for single sideband and are also general coverage. SSB receivers has better selectivity and a product detector. I have plenty single-ended audio amplifiers (one audio output tube) and they sounded good.

One receiver that will outperform most tube radios is the Heathkit SB-310 with good crystal filters, dual conversion and product detector for SSB. It covers the shortwave broadcast bands (but not all SW frequencies) and the CB band. The audio sounds good to me. The radio also has a high fidelity output jack for a separate outboard amplifier. Make sure at least the 6.0 kHz and 2.1 kHz filters are installed. Some also has the optional 500Hz CW filter. It also receives 80, 40 and 20 meter ham bands. Not much activity on 160, 15 and 10 meters ham. The CB band can be changed to 15 or 10 meters with a crystal change. 10 meters has 500kHz coverage. Around $200.

Another receiver like the Heathkit SB-310, but full coverage from AM broadcast to 34MHz is the Hallicrafters SX-122. It is dual conversion and has a product detector. It also has three filter positions- 5000, 2400 and 500 Hz. About $350.

If you do not mind to adjust a BFO and ride the RF gain, the Hallicrafters SX-71 is a very good receiver. It has three IFs that make for good selectivity plus double conversion to remove images.. The front end is of modern tube design. Change the 6BA6 RF amp to a 6BZ6 and change the third IF 6SH7 to a 6AC7 and enjoy a fairly quiet and sensitive receiver. About $150.

_________________
NAVY JACK FLAG- 'Don't Tread on Me'


Last edited by jimbenedict on Nov Sun 22, 2020 6:46 pm, edited 4 times in total.

Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 4:07 am 
Member
User avatar

Joined: Jun Sun 19, 2011 2:31 pm
Posts: 7694
The Super Pro receivers, prior to the SP-600 which is very different than the earlier models, have excellent audio. Those models have continuously variable bandwidth via mechanical control of the IF transformer coupling and sound excellent with good quality AM broadcast material. In the narrow setting with crystal filter engaged, the selectivity is very good. The biggest drawback to the Super Pro series is the receiver is very large and heavy and it has a large and heavy external power supply. The build and component quality is superb. Note that there were a lot of variants, particularly for the military, so make sure you get one with the frequency range that you want. Some do NOT include the AM broadcast band but instead offer either low frequency coverage or coverage to the top of the shortwave range instead so choose which model fits your needs.

BUT if you want good sideband performance (proper selectivity, stability, and a good detector) then you are looking at much later receivers and then you are giving up some of the excellent audio of the earlier models.

The Hammarlund HQ-180 with built in SSB product detector and proper selectivity would fit your needs as a very good performing general coverage vintage receiver as would the much more difficult to find National NC-400. The Hallicrafters SX-100 doesn't have a built in product detector BUT it has plenty of BFO injection and does a nice job on SSB and has better audio recovery than the later Hammarlund HQ series. The earlier SX-96 performance is very close to the SX-100 and is also a nice set.

A Superpro with the added HC-10 SSB adapter is a very versatile and good performing receiver as would be a Hammarlund HQ-160.

There is no receiver which excels or is perfect on all dimensions so you have to decide what performance categories (including styling and ergonomics) best fit YOUR tastes.

Rodger WQ9E


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 4:19 am 
Member

Joined: Jan Tue 07, 2020 1:41 am
Posts: 3567
Location: Fenton, MI 48430
rsingl wrote:
The Super Pro receivers, prior to the SP-600 which is very different than the earlier models, have excellent audio. Those models have continuously variable bandwidth via mechanical control of the IF transformer coupling and sound excellent with good quality AM broadcast material. In the narrow setting with crystal filter engaged, the selectivity is very good. The biggest drawback to the Super Pro series is the receiver is very large and heavy and it has a large and heavy external power supply. The build and component quality is superb. Note that there were a lot of variants, particularly for the military, so make sure you get one with the frequency range that you want. Some do NOT include the AM broadcast band but instead offer either low frequency coverage or coverage to the top of the shortwave range instead so choose which model fits your needs.

BUT if you want good sideband performance (proper selectivity, stability, and a good detector) then you are looking at much later receivers and then you are giving up some of the excellent audio of the earlier models.

The Hammarlund HQ-180 with built in SSB product detector and proper selectivity would fit your needs as a very good performing general coverage vintage receiver as would the much more difficult to find National NC-400. The Hallicrafters SX-100 doesn't have a built in product detector BUT it has plenty of BFO injection and does a nice job on SSB and has better audio recovery than the later Hammarlund HQ series. The earlier SX-96 performance is very close to the SX-100 and is also a nice set.

A Superpro with the added HC-10 SSB adapter is a very versatile and good performing receiver as would be a Hammarlund HQ-160.

There is no receiver which excels or is perfect on all dimensions so you have to decide what performance categories (including styling and ergonomics) best fit YOUR tastes.

Rodger WQ9E

The SP 400 is my second favorite receiver. Variable bandwidth is very effective. Audio is as good as it gets. It has a Hi-Fi audio amp inside.

_________________
NAVY JACK FLAG- 'Don't Tread on Me'


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 5:23 am 
Member
User avatar

Joined: Jul Fri 21, 2017 9:58 pm
Posts: 1428
Location: Erie, Pa.
jimbenedict wrote:
I read you want general coverage. It is best to know your budget as prices vary a lot. A very good receiver with great audio having push-pull audio output is the National NC-183D. The 183D is dual conversion thus has no images on shortwave. The NC-183 is not dual conversion. I find the NC-183D for $250-$350. A deal may be had on the QTH.com site with a wanted ad.

However, you want a SSB receiver? Most tube receivers are not designed for single sideband and are also general coverage. SSB receivers has better selectivity and a product detector. I have plenty single-ended audio amplifiers (one audio output tube) and they sounded good.

One receiver that will outperform most tube radios is the Heathkit SB-310 with good crystal filters, dual conversion and product detector for SSB. It covers the shortwave broadcast bands (but not all SW frequencies) and the CB band. The audio sounds good to me. The radio also has a high fidelity output jack for a separate outboard amplifier. Make sure at least the 6.0 kHz and 2.1 kHz filters are installed. Some also has the optional 500Hz CW filter. It also receives 80, 40 and 20 meter ham bands. Not much activity on 160, 15 and 10 meters ham. The CB band can be changed to 15 or 10 meters with a crystal change. 10 meters has 500kHz coverage. Around $200.

Another receiver like the Heathkit SB-310, but full coverage from AM broadcast to 34MHz is the Hallicrafters SX-122. It is dual conversion and has a product detector. It also has three filter positions- 5000, 2400 and 500 Hz. About $350.

If you do not mind to adjust a BFO and ride the RF gain, the Hallicrafters SX-71 is a very good receiver. It has three IFs that make for good selectivity. The front end is of modern tube design. Change the 6BA6 RF amp to a 6BZ6 and change the third IF 6SH7 to a 6AC7 and enjoy a fairly quiet and sensitive receiver. About $150.

Thank you for your time in writing such a great post, full of helpful information.
I come here because I love talking radio.
I am listening to WGM, "Chicago's Very Own", on my 1952 Philip's BX632A50, which I have fallen in love with.
I am in Erie Pa..
I was checking out an RBH-1 WW2 Navy receiver. In my teens, my family visited the river camp of a retired Navy WW2 vet, an officer on a destroyer in the Pacific theater.
He had one of these in his living room, and instead of sleeping, I was up into the wee hours listening to everything.
I am looking to add a military grade cold war classic to my collection that had general coverage and can demodulate ssb.
I once had a Hallicrafters SX-99 that was tube and did a fine job on ssb.
My best memory was listening to Royal Thai Radio at sunset one summer night!

_________________
Tim, N3YQV
"I'm SHOCKED! SHOCKED, I tell you!"


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 5:47 am 
Member
User avatar

Joined: Jul Fri 21, 2017 9:58 pm
Posts: 1428
Location: Erie, Pa.
rsingl wrote:
The Super Pro receivers, prior to the SP-600 which is very different than the earlier models, have excellent audio. Those models have continuously variable bandwidth via mechanical control of the IF transformer coupling and sound excellent with good quality AM broadcast material. In the narrow setting with crystal filter engaged, the selectivity is very good. The biggest drawback to the Super Pro series is the receiver is very large and heavy and it has a large and heavy external power supply. The build and component quality is superb. Note that there were a lot of variants, particularly for the military, so make sure you get one with the frequency range that you want. Some do NOT include the AM broadcast band but instead offer either low frequency coverage or coverage to the top of the shortwave range instead so choose which model fits your needs.

BUT if you want good sideband performance (proper selectivity, stability, and a good detector) then you are looking at much later receivers and then you are giving up some of the excellent audio of the earlier models.

The Hammarlund HQ-180 with built in SSB product detector and proper selectivity would fit your needs as a very good performing general coverage vintage receiver as would the much more difficult to find National NC-400. The Hallicrafters SX-100 doesn't have a built in product detector BUT it has plenty of BFO injection and does a nice job on SSB and has better audio recovery than the later Hammarlund HQ series. The earlier SX-96 performance is very close to the SX-100 and is also a nice set.

A Superpro with the added HC-10 SSB adapter is a very versatile and good performing receiver as would be a Hammarlund HQ-160.

There is no receiver which excels or is perfect on all dimensions so you have to decide what performance categories (including styling and ergonomics) best fit YOUR tastes.

Rodger WQ9E

Thanks, Roger!

I would be interested to hear your opinion of the SP-600, and in what ways is it different?

Thank you for the wonderful information on these beautiful old boatanchors!

_________________
Tim, N3YQV
"I'm SHOCKED! SHOCKED, I tell you!"


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 6:12 am 
Member

Joined: Jan Tue 07, 2020 1:41 am
Posts: 3567
Location: Fenton, MI 48430
The Hallicrafters SX-122 as mentioned along with the SB-310 are light weight receivers and not near the SP-600 in weight and Mil Spec design. You want the JX-21 or similar with the ceramic capacitors. Eliminates about 20 capacitors with some in difficult to access to replace due to ceramic caps rarely go bad.

_________________
NAVY JACK FLAG- 'Don't Tread on Me'


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 6:25 am 
Member
User avatar

Joined: Jul Fri 21, 2017 9:58 pm
Posts: 1428
Location: Erie, Pa.
jimbenedict wrote:
The Hallicrafters SX-122 as mentioned along with the SB-310 are light weight receivers and not near the SP-600 in weight and Mil Spec design. You want the JX-21 or similar with the ceramic capacitors. Eliminates about 20 capacitors with some in difficult to access to replace due to ceramic caps rarely go bad.

Thanks!
I take it the letter J denotes a military contract.
No external power supply needed, not sure if there is a terminal for both 3 ohm and 600 ohm speaker.

Boy, bet you could do some dx'ing with that!

_________________
Tim, N3YQV
"I'm SHOCKED! SHOCKED, I tell you!"


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 7:13 am 
Member

Joined: Jan Tue 07, 2020 1:41 am
Posts: 3567
Location: Fenton, MI 48430
Dalton wrote:
jimbenedict wrote:
The Hallicrafters SX-122 as mentioned along with the SB-310 are light weight receivers and not near the SP-600 in weight and Mil Spec design. You want the JX-21 or similar with the ceramic capacitors. Eliminates about 20 capacitors with some in difficult to access to replace due to ceramic caps rarely go bad.

Thanks!
I take it the letter J denotes a military contract.
No external power supply needed, not sure if there is a terminal for both 3 ohm and 600 ohm speaker.

Boy, bet you could do some dx'ing with that!

I owned a lot of receivers because I was curious how they performed. The SP-600 is a very nice receiver. Use a 70.7 volt transformer to convert the 600 ohms to 8 or 4 ohms.

_________________
NAVY JACK FLAG- 'Don't Tread on Me'


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 8:04 am 
Member

Joined: Feb Sun 16, 2020 7:45 am
Posts: 80
Hi Dalton,

I am not quite clear as to what your budget is, and it seems like you are mostly interested in AM short wave listening with possible SSB for the amateur bands. I will give you a little of my experience with some mid-range priced receivers I have used in the past or currently own. I had a Hammarlund HQ-140XA and liked it a lot-excellent AM performance and very stable. Unfortunately I sold it before moving. Currently I have an SX-99, NC-98, and NC-109 and I have recapped them all as well as doing other steps to bring them up to proper operating condition. Both the SX-99 and the NC-98 perform well on the shortwave bands up to say 20 MHz, but being single conversion designs they suffer from images at higher frequencies. Both have good audio quality, and they both drift and need a period of time to warm up. They can be used for SSB reception, but without a product detector it is important to reduce the RF gain and use BFO pitch to copy the signal. The NC-109 does have a product detector for better SSB reception and it is much less prone to drift than the SX-99 and NC-98. I have recapped an NC-190 which does have double conversion, a product detector, improved selectivity and interestingly has selectable bandspread dials for the ham and shortwave bands. I think you would like the NC-190 if you can find one in good condition. Lastly I am about to start recapping an SX-122, which as others have mentioned is a very fine receiver for the price with double conversion, a product detector, and improved selectivity.

So the question is where are you going to find a receiver like the others and I have mentioned that is in reasonably good operating and cosmetic condition? I would be very cautious about those sellers on eBay who pick up a radio at an estate sale, know nothing about it, and just plugged it in to show it lights up. A better bet would be to find one that has been refurbished or is being sold by a collector who is just trying to downsize his/her collection. Besides eBay you could look at other sites like QRZ.com and eHam.com where it is mostly ham radio operators who are selling equipment.

Good luck and have fun in this great hobby!

73s, Scott, N6CIC


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 3:31 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 1571
Location: Morris Plains, N.J. 07950
One other factor to consider is your technical/repair skills. At a minimum, older radio will need to have its filter caps and paper caps replaced.

The Hammarlunds are wonderful receivers, but the SP-200 and the SP-600 require removal of the RF deck to replace the caps inside the deck. If I remember correctly, the SP-400 does not require as much disassembly. The BC-1004, a military version of the SP-200, is my favorite receiver, but removal of the RF deck can be a daunting task if you haven't worked on a few of these sets. I was sweating the entire time I had the deck out on mine. The National receivers don't require as much disassembly for cap replacement.

Since you cut your teeth on an RBH and have fond memories of it, how about a National NC-100ASD or an National NC-156? They perform well. While they don't have product detectors for SSB, you can usually listen to SSB by learning the art of using the BFO and riding the RF Gain control. I have an NC-100ASD and really like it. Those models are out there for sale and usually don't cost an arm and a leg.


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 4:38 pm 
Member

Joined: Jan Tue 07, 2020 1:41 am
Posts: 3567
Location: Fenton, MI 48430
Regarding rebuilding, the easiest receivers mentioned to rebuild are the Heathkit SB-310, Hallicrafters SX-122 and SX-71. I do find Collins R-388 for about $350 at times, but heavy shipping weight adds about $75. I assume your budget is $175 to $250? Hallicrafters SX-71 $150. Heathkit SB-301 $200. Hallicrafters SX122 $250 to $350.

_________________
NAVY JACK FLAG- 'Don't Tread on Me'


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 7:37 pm 
Member
User avatar

Joined: Jul Fri 21, 2017 9:58 pm
Posts: 1428
Location: Erie, Pa.
jimbenedict wrote:
Dalton wrote:
jimbenedict wrote:
The Hallicrafters SX-122 as mentioned along with the SB-310 are light weight receivers and not near the SP-600 in weight and Mil Spec design. You want the JX-21 or similar with the ceramic capacitors. Eliminates about 20 capacitors with some in difficult to access to replace due to ceramic caps rarely go bad.

Thanks!
I take it the letter J denotes a military contract.
No external power supply needed, not sure if there is a terminal for both 3 ohm and 600 ohm speaker.

Boy, bet you could do some dx'ing with that!

I owned a lot of receivers because I was curious how they performed. The SP-600 is a very nice receiver. Use a 70.7 volt transformer to convert the 600 ohms to 8 or 4 ohms.


Thanks!
Hopefully the performance would be worth the need for the extras!

_________________
Tim, N3YQV
"I'm SHOCKED! SHOCKED, I tell you!"


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 7:48 pm 
Member
User avatar

Joined: Jul Fri 21, 2017 9:58 pm
Posts: 1428
Location: Erie, Pa.
Scott10k wrote:
Hi Dalton,

I am not quite clear as to what your budget is, and it seems like you are mostly interested in AM short wave listening with possible SSB for the amateur bands. I will give you a little of my experience with some mid-range priced receivers I have used in the past or currently own. I had a Hammarlund HQ-140XA and liked it a lot-excellent AM performance and very stable. Unfortunately I sold it before moving. Currently I have an SX-99, NC-98, and NC-109 and I have recapped them all as well as doing other steps to bring them up to proper operating condition. Both the SX-99 and the NC-98 perform well on the shortwave bands up to say 20 MHz, but being single conversion designs they suffer from images at higher frequencies. Both have good audio quality, and they both drift and need a period of time to warm up. They can be used for SSB reception, but without a product detector it is important to reduce the RF gain and use BFO pitch to copy the signal. The NC-109 does have a product detector for better SSB reception and it is much less prone to drift than the SX-99 and NC-98. I have recapped an NC-190 which does have double conversion, a product detector, improved selectivity and interestingly has selectable bandspread dials for the ham and shortwave bands. I think you would like the NC-190 if you can find one in good condition. Lastly I am about to start recapping an SX-122, which as others have mentioned is a very fine receiver for the price with double conversion, a product detector, and improved selectivity.

So the question is where are you going to find a receiver like the others and I have mentioned that is in reasonably good operating and cosmetic condition? I would be very cautious about those sellers on eBay who pick up a radio at an estate sale, know nothing about it, and just plugged it in to show it lights up. A better bet would be to find one that has been refurbished or is being sold by a collector who is just trying to downsize his/her collection. Besides eBay you could look at other sites like QRZ.com and eHam.com where it is mostly ham radio operators who are selling equipment.

Good luck and have fun in this great hobby!

73s, Scott, N6CIC

Thank you, Scott!
Very good hints in your post, most grateful!
My budget for the radio I am seeking would be about $400 including shipping, perhaps a bit over for a great radio.

I am on hold right now, waiting to see if someone is willing to sell me a radio I really want.

I wanted to get some alternatives in case the deal doesn't go through.

_________________
Tim, N3YQV
"I'm SHOCKED! SHOCKED, I tell you!"


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 7:53 pm 
Member
User avatar

Joined: Jul Fri 21, 2017 9:58 pm
Posts: 1428
Location: Erie, Pa.
jimbenedict wrote:
Regarding rebuilding, the easiest receivers mentioned to rebuild are the Heathkit SB-310, Hallicrafters SX-122 and SX-71. I do find Collins R-388 for about $350 at times, but heavy shipping weight adds about $75. I assume your budget is $175 to $250? Hallicrafters SX-71 $150. Heathkit SB-301 $200. Hallicrafters SX122 $250 to $350.

Budget is a out $400 including shipping, perhaps a bit more for a great radio.

Am waiting now to see if a deal goes through, will know beginning of December.

Wanted to see what the other options might be if this doesn't happen.

Plan "B" and "C" are always good to have.

_________________
Tim, N3YQV
"I'm SHOCKED! SHOCKED, I tell you!"


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Sun 22, 2020 7:56 pm 
Member
User avatar

Joined: Jul Fri 21, 2017 9:58 pm
Posts: 1428
Location: Erie, Pa.
Joe Connor wrote:
One other factor to consider is your technical/repair skills. At a minimum, older radio will need to have its filter caps and paper caps replaced.

The Hammarlunds are wonderful receivers, but the SP-200 and the SP-600 require removal of the RF deck to replace the caps inside the deck. If I remember correctly, the SP-400 does not require as much disassembly. The BC-1004, a military version of the SP-200, is my favorite receiver, but removal of the RF deck can be a daunting task if you haven't worked on a few of these sets. I was sweating the entire time I had the deck out on mine. The National receivers don't require as much disassembly for cap replacement.

Since you cut your teeth on an RBH and have fond memories of it, how about a National NC-100ASD or an National NC-156? They perform well. While they don't have product detectors for SSB, you can usually listen to SSB by learning the art of using the BFO and riding the RF Gain control. I have an NC-100ASD and really like it. Those models are out there for sale and usually don't cost an arm and a leg.


Thank you for the great information.

I am learning quite a lot here, and it is good to know there are others who appreciate these works of craftsmanship!

_________________
Tim, N3YQV
"I'm SHOCKED! SHOCKED, I tell you!"


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Tue 24, 2020 8:15 pm 
Member
User avatar

Joined: Jul Fri 21, 2017 9:58 pm
Posts: 1428
Location: Erie, Pa.
jimbenedict wrote:
Regarding rebuilding, the easiest receivers mentioned to rebuild are the Heathkit SB-310, Hallicrafters SX-122 and SX-71. I do find Collins R-388 for about $350 at times, but heavy shipping weight adds about $75. I assume your budget is $175 to $250? Hallicrafters SX-71 $150. Heathkit SB-301 $200. Hallicrafters SX122 $250 to $350.

I settled on the National NC-183D.
I had an SP-600 Hammarlund in my sights, but it was slated local pickup, the guy didn't want to pack it, and the cost of the radio plus packing and shipping costs were too much.

I also had visions of the thing getting broken enroute, handlers aren't kind to extremely heavy boxes, I know this having worked for DHL at one point.

The National will be pretty much ready to go when I add a speaker, and won't require a transformer or antenna tuner. I also won't get a hernia carrying it up steps, at 63, this is important!

I hear tell this set has a product detector for SSB, and reputedly wonderful audio.

The 5 star rating from eham didn't hurt, either.

I am sure it will need some TLC.


"The "D" in the model number signifies dual conversion while the earlier NC-183 , introduced in 1947,was single conversion. Both the NC-183 and the NC-183D use push-pull 6V6GT output tubes for "Hi-Fi" sound. Both have tone controls and an RCA jack for phono input and are known for excellent sound from the optional 10 inch speaker. Both use VR-150 voltage regulator tubes. Most of the tubes in the NC-183D are 7 pin miniature types such as the five 6BA6 tubes used for two RF stages and three IF stages. A pair of 6BE6 tubes are used for the converter stages. The NC-183 uses octal tubes for those functions and uses a separate oscillator tube.
As purchased, this example used a 6J5 for phase inverter. A later variation used a dual triode 6SN7 for that function with one of the triodes serving as S-meter amplifier."

https://people.ohio.edu/postr/bapix/NC-183D.htm


From Radiomuseum -

"USA)
Manufacturer / Brand: National Company; Cambridge & Malden (MA)
alternative name

National Toy Co.
Brand
Thrillbox
Year: 1952–1958 Category: Amateur-Receiver (amateur bands, may include broadcast bands)
Valves / Tubes 16: 6BA6 6BA6 6BE6 6BE6 6BA6 6BA6 6BA6 6AL5 6AH6 6SJ7 6AL5 6SJ7 6SN7 6J5 6V6GT 6V6GT 5U4G 0B2
Main principle Superhet, double/triple conversion; ZF/IF 1720/455 kHz
Wave bands Broadcast plus more than 2 Short Wave bands.
Details
Power type and voltage Alternating Current supply (AC) / 115 / 230 Volt
Loudspeaker - For headphones or amp.
Power out 8 W (unknown quality)
from Radiomuseum.org Model: NC-183D - National Company; Cambridge &
Material Metal case
Shape Tablemodel, with any shape - general.
Dimensions (WHD) 501 x 260 x 425 mm / 19.7 x 10.2 x 16.7 inch
Notes coverage .540 - 31 and 48-56 MHz, bandspread in ham bands, AM, CW (BFO);
double conversion on frequencies above 4 MHz;
table model also referenced as NC-183DT
optional NC-183DTS external speaker, NFM-83-50 narrow band FM-adaptor, SOJ-3 select-o-ject
F.Osterman (Shortwave Receivers-Past & Pres.) mentions VR150 instead of 0B2, not otherwise verified.
Net weight (2.2 lb = 1 kg) 29.4 kg / 64 lb 12.1 oz (64.758 lb)
Price in first year of sale 370.00 $
Source of data"

Coming from Canada, so it will take a while to get here.

_________________
Tim, N3YQV
"I'm SHOCKED! SHOCKED, I tell you!"


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Tue 24, 2020 8:59 pm 
Member
User avatar

Joined: Jun Sun 19, 2011 2:31 pm
Posts: 7694
Dalton,

The NC-183D is a solid National receiver. There are two distinct versions with the earlier using a 6J5 as the phase inverter for the output stage and the later version using a 6SN7 with one section as a phase inverter and the other as a S meter amp. Just make sure to use the correct schematic for the receiver that you have to avoid confusion.

Some National receivers of this era left the factory with a .1uf capacitor from one of the rectifier plate pins to ground. If your receiver has this, remove the capacitor because it isn't needed. If it fails shorted it WILL take out the transformer before the fuse can open and a lot of National receivers ended up with new power transformers because of this useless capacitor. It was left out in later production and probably cost National a bit in warranty dollars even back then.

Regardless of version, it is very common to find the 47K screen resistors used throughout the RF and IF sections to have drifted to many times their marked value. This is from a combination of less than stellar resistor quality combined with these resistors operating at near their rated dissipation in many of these positions. Check the screen voltage (or resistor value) on them but if you find any of them out I would just replace all of them. This was necessary on both NC-183D receivers I restored along with the NBS variant based upon the NC-183D. It is a known issue with this set.

Otherwise there will be a few paper type capacitors (primarily the larger value units) that should be replaced but even in the early production most of the capacitors are either mica or ceramic disc. The filter capacitors will likely need replacement, definitely replace the output stage cathode bypass cap because leakage or a short here will potentially take out the audio output transformer and possibly the power transformer. All of these that I have been around came from the factory with reliable ceramic discs in the coupling/DC blocking position for the output tube control grids but if by chance your radio was built with paper caps here then replace them for the same reason you replace the output stage bypass capacitor.

Unlike many receivers, several National sets of this era hold the B+ return slightly above ground to develop bias for the output stage and RF gain control network. It has a separate filter capacitor for this section which is 25 uf @ 50 volts. Some versions of the manual incorrectly list this as a 25 pf capacitor so ignore the manual and use the marked value on the schematic and existing capacitor when replacing. Observe proper polarity when replacing this bias supply capacitor remembering that the negative lead of an electrolytic capacitor goes to the most negative potential part of the circuit, in this case it is the bias bus and not ground.

Rodger WQ9E


Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Tue 24, 2020 9:22 pm 
Member
User avatar

Joined: Sep Wed 10, 2014 2:01 am
Posts: 2285
Location: Costa Mesa, California
You should enjoy this radio. It does not have a product detector but easily receives SSB. Mine was in terrible condition but was worth the effort to restore.

Norm


Attachments:
National 1.jpg
National 1.jpg [ 158.28 KiB | Viewed 542 times ]
Bottom.jpg
Bottom.jpg [ 292.94 KiB | Viewed 542 times ]

_________________
KK6IYM
Top
 Profile  
 
 Post subject: Re: National vs. Hammarland General Coverage Receivers
PostPosted: Nov Tue 24, 2020 9:47 pm 
Moderator

Joined: Jan Thu 01, 1970 1:00 am
Posts: 18167
Location: Utica, NY 13502 (USA)
I'm glad you settled on a 183D. Besides the usual need to replace the paper and electrolytic caps, mine also suffered from out-of-tolerance resistors. The 470K units in the AGC circuit had gone way high or open. This led to several 6BA6 tubes developing grid emission which was a problem even after the resistors were replaced.

Properly restored and aligned, you will love this receiver especially its no-nonsense control layout and push-pull audio.

Dave


Top
 Profile  
 
Post New Topic Post Reply  [ 41 posts ]  Moderator: Sandy Go to page 1, 2, 3  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: Majestic-12 [Bot] and 18 guests



Search for:
Jump to:  


































Privacy Policy :: Powered by phpBB