Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

donate to eham
   Home   Help Search  
Pages: Prev 1 [2] 3 Next   Go Down
  Print  
Author Topic: Boat Anchors- How much Transceiver do you really need?  (Read 28210 times)
KM1H
Member

Posts: 5096




Ignore
« Reply #15 on: December 30, 2015, 09:11:46 AM »

The highest power transceiver here is a National NCX-1000 and the numbers signify power input which is the way the FCC rules required it back then.

Excellent sounding SSB as well as AM and with enough power to be heard. Low production but show up regularly.

Carl
Logged
KE0ZU
Member

Posts: 458


WWW

Ignore
« Reply #16 on: December 30, 2015, 08:05:54 PM »

Another nice National is the NCX-5.  This is a pic of my first one with a remote VFO from years ago.   I've had two additional units since, with the newest one, which also has the remote VFO, is in line for a tune-up.   You want to get a Mark II which has a solid state balanced mixer.   
Logged

Regards, Mike
https://mikeharrison.smugmug.com/
Pics and bold print are usually links.
KG8LB
Member

Posts: 408




Ignore
« Reply #17 on: December 30, 2015, 08:22:02 PM »

Seems I recall a fellow advertising  National NCX-1000 radios for quite some time after National went toes-up . A friend of mine from Mass.  bought a couple back then and reported that the guy had a "trailer load" of National gear , parts and partials of much of the last products .  He may have advertised in QST or CQ back in the days .

  That NCX-5 actually would interest me far more . Pretty sharp setup ! Plenty of power too .
Logged
SM0AOM
Member

Posts: 254




Ignore
« Reply #18 on: December 31, 2015, 07:14:31 AM »

It is an intriguing question in which extent the "Boatanchor" performance of yesteryear would be sufficient to permit successful operations on the amateur HF bands today.

What we know is that the RF environment has changed considerably during the past two or three decades, with the noise floor rising and general activity as well as the maximum signal levels diminishing. The situation that was prevalent in especially Europe in the 1980's with a continuing "arms race" among the HF broadcasters and the general amateur radio activity on a high level will not return.
Looking into the performance of the better of yesteryears transceivers and receivers we find that IP3 values of about -15 dBm were common. These translate into dynamic ranges in the order of 65 dB close-spaced and 80 dB wide-spaced. In the era of 40 m filled to the brim with megawatt ERP broadcasters this was obviously insufficient.  

We who are still dealing with professional HF have noticed a marked decrease of the channel occupancy today as compared to the compilation from the 80's and 90's that formed the underlying material for the "Gott-Laycock congestion model" which has formed the basis for the systems planning of many contemporary HF radio architectures.

Receiver performance such as the specifications for the Telefunken/Deutsche Aerospace E1800 were derived from this RF environment. Looking at channel occupancy and level statistics of today, the levels are much more less, current spectral plots taken as performance verfications on a 12 dBi horizontally polarized LP antenna system pointed due south shows that levels seldom exceed -30 dBm, as compared to the -10 dBm or higher levels common 20 or 30 years ago.  The adjacent band levels encountered from the antenna systems  were sufficient to overload the 51S-1 receivers used for air-ground watchkeeping purposes in the early 80's-

Another aspect is the transmitter spectral purity which has detoriated considerably since "yesteryear". If the SSB adjacent channel suppression is no better than, say, -70 dBc at +/- 10 kHz, no receiver performance figures can offset this fact.  
Few practical operating situations  require higher receive dynamic ranges than 80 dB seen in this perspective.

It appears that the transmitter and receiver performance figures were better matched in the days of the Collins S-line, SB-102, Drake TR-4 or Trio TS-520.

The performance offered from these general forms of classic equipment should be sufficient for general operating seen in the perspective of diminishing HF spectrum usage, both amateur, commercial and broadcasting.
Logged
N8FVJ
Member

Posts: 867




Ignore
« Reply #19 on: December 31, 2015, 09:46:41 AM »

The NCX-5 MKII 100 watt PEP output can be increased to 300 watts PEP. Replace the 6BJ6 final tubes with 6LQ6 or the heavy duty 6MJ6. The NCX-5 matching power supply has the same power transformer as the NCX-500 power supply. Remove the NCX-5 power supply HV input swinging choke, resistor bank for minimum Lcrit & the three original HV capacitors.

Add four 400 volt 330uF snap-in type capacitors in series. Use a 50K 5 watt resistor across each capacitor as a safety bleeder. Install a 5 amp CCS duty thermistor on the 120 volt AC line input to limit the power supply start up surge. The modified power supply will now provide approximately 1100 volts DC. The NCX-5 also has the NCX-500 plate tuning capacitor with wide spacing in-between the plates.
Logged
N9FB
Member

Posts: 2362




Ignore
« Reply #20 on: December 31, 2015, 07:22:30 PM »

Give me a TS-520S, Drake TR4C, TS-120S, or HW series rig any day. Or even a Collins. Today's rigs are WAY too overloaded with switches, menus, and other frills that take the fun out of real operating. The vast majority of hams today probably don't use 80% of what their rig does. And if that one proprietary chip goes out and a replacement isn't available anymore then you have lost several functions that you'll never get to use anymore.

agree 100% on the modern overload w/ switches/menus/& frills!  I got back in the hobby after 30 years after finding a Ten-Tec Scout on Craigs list.  very few buttons and a lot of fun to use.  then I got an Argonaut V, then an old Omni C (had been my dream rig back int he day) until finding a used Jupiter.  The Jupiter is extremely easy to operate in terms of menus and number & size of buttons, but it also has a lot of modern amenities that for me make it the perfect compromise between new and old.  

a year ago I sold my Jupiter because I could get a Kenwood 590s at a GREAT price from HRO because the 590SG was about to come out. It was my first ever brand new rig.  Big mistake.  The rig is decent but there are so many buttons (and they are so tiny) you practically need raccoon hands & dexterity to operate it. I much prefer the Jupiter's audio which is far more pleasant to the ear on both CW and SSB (yes i got to know the equalizer on the 590s, but still).  The Jupiter is a study in ease of use yet offering a lot at the same time.  
Needless to say, I sold the 590s and got another Jupiter.  

ymmv...  73 and HNY
Logged
KE0ZU
Member

Posts: 458


WWW

Ignore
« Reply #21 on: December 31, 2015, 10:30:19 PM »

Jim said;
Quote
The NCX-5 matching power supply has the same power transformer as the NCX-500 power supply.
I could be wrong, but, don't think so.  National transformer P/Ns are different and so are choke P/Ns. NC5 power trans is C50871, and 500 is C51325.   Voltages aren't at all similar/multiples either.

I own/owned both and don't remember anything but the case and power connectors being the same in both supplies, even though they were quite similar topology.





PS Disregard pencil markups in 500 schematic.





Logged

Regards, Mike
https://mikeharrison.smugmug.com/
Pics and bold print are usually links.
N8FVJ
Member

Posts: 867




Ignore
« Reply #22 on: January 01, 2016, 11:49:30 AM »

My research shows same transformer part number. The reason voltages are substantially different in-between the two power supplies is the NCX-5 power supply is choke input or approximately .9 times the HV secondary input. 800 volts x approximately .9 = 720 volts DC (no load). Capacitor input provides 800 volts x 1.4 = 1120 volts DC (no load).

I will try to find the documents showing same transformer part number & post it here. BTW- The mod works with my NCX-5 without excessive transformer operating temperatures and others have performed the same mod.
Logged
N8FVJ
Member

Posts: 867




Ignore
« Reply #23 on: January 01, 2016, 12:17:05 PM »

You are correct, not same power transformer. I did this mod so many years ago I may have actually rebuilt a NCX 500 (not NCX-A)power supply and plugged that into the NCX-5. It worked well.
Logged
KE0ZU
Member

Posts: 458


WWW

Ignore
« Reply #24 on: January 01, 2016, 02:01:10 PM »

Jim, interesting idea nonetheless. Should I run across an NC-500 or its power supply some day I may very well get it. 

All these National transceivers are seldom traded/sold any more.    On Ebay, the number of listings by model seems to be NCX-3, NCL-2000, and lastly the NCX 5.   Items like the HRO-500, and NCX-1000 show up occasionally but are even more rare.   I don't think I've seen an NCX-200 or NCX-500 since I sold mine 5 years or more ago.
Logged

Regards, Mike
https://mikeharrison.smugmug.com/
Pics and bold print are usually links.
KM1H
Member

Posts: 5096




Ignore
« Reply #25 on: January 01, 2016, 06:12:49 PM »

Quote
The NCX-5 MKII 100 watt PEP output can be increased to 300 watts PEP. Replace the 6BJ6 final tubes with 6LQ6 or the heavy duty 6MJ6. The NCX-5 matching power supply has the same power transformer as the NCX-500 power supply. Remove the NCX-5 power supply HV input swinging choke, resistor bank for minimum Lcrit & the three original HV capacitors.

Add four 400 volt 330uF snap-in type capacitors in series. Use a 50K 5 watt resistor across each capacitor as a safety bleeder. Install a 5 amp CCS duty thermistor on the 120 volt AC line input to limit the power supply start up surge. The modified power supply will now provide approximately 1100 volts DC. The NCX-5 also has the NCX-500 plate tuning capacitor with wide spacing in-between the plates.

As the person who designed the NCX-500 from the National 200 (aka NCX-200) on his lunch hour in the Service Dept over a week or so I wouldnt butcher the NCX-5. It was a rush job, not budgeted, and a last gasp effort to get sales during the power wars of the time.
The 6LQ6's get no cooling, are harder to find than 6JB6 or 12JB6's, really should be a matched pair, dont neutralize without changes, and otherwise destroy a classic rig. Besides, the 500 PS is only good on SSB without processing since it isnt rated for anything else at that power level.

If youre that power hungry get a Swan or add a CB amp.

I was also on the NCX-1000 design team...officially

Carl
Logged
K9AXN
Member

Posts: 442


WWW

Ignore
« Reply #26 on: January 02, 2016, 07:23:59 PM »


As the person who designed the NCX-500 from the National 200 (aka NCX-200) on his lunch hour in the Service Dept over a week or so I wouldnt butcher the NCX-5. It was a rush job, not budgeted, and a last gasp effort to get sales during the power wars of the time.
The 6LQ6's get no cooling, are harder to find than 6JB6 or 12JB6's, really should be a matched pair, dont neutralize without changes, and otherwise destroy a classic rig. Besides, the 500 PS is only good on SSB without processing since it isnt rated for anything else at that power level.

If youre that power hungry get a Swan or add a CB amp.

I was also on the NCX-1000 design team...officially

Carl

Carl, what areas of the NCX-1000 design did you participate and do you have the service and design review notes?

I had them years ago but simply cannot find them.  Working with a fellow that is making one from two.

Regards Jim
Logged
KG8LB
Member

Posts: 408




Ignore
« Reply #27 on: January 03, 2016, 08:05:28 AM »

   I don't think I've seen an NCX-200 or NCX-500 since I sold mine 5 years or more ago.


  You got money for yours ?   I gave mine away ! Roll Eyes
Logged
K9AXN
Member

Posts: 442


WWW

Ignore
« Reply #28 on: January 03, 2016, 05:30:09 PM »

Carl,

I found two of the design review notes regarding NCX-1000 final configuration but haven't found the rest yet.

Would appreciate a response regarding the part of that radio you participated and if you still have the notes.

Appreciate anything you can do.  Hard to find anyone who worked with that radio.

Kindest regards Jim
« Last Edit: January 03, 2016, 07:12:42 PM by K9AXN » Logged
KE0ZU
Member

Posts: 458


WWW

Ignore
« Reply #29 on: January 03, 2016, 07:15:21 PM »

Quote
You got money for yours ?   I gave mine away !
You were in too big of a rush.   Wash, Wax, and pretty pics, it won't take long for offers to start rollin in. Grin
Logged

Regards, Mike
https://mikeharrison.smugmug.com/
Pics and bold print are usually links.
Pages: Prev 1 [2] 3 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!