Ameco VHF converter with NC300

[ke7trp]

 I found an ameco "VHF" converter model CN in the store room.  It has one tube and two 6ds4s.  Looks to be complete.  There is NO Xtal in the socket.  I guess I need to make an 8 pin plug to go from it to the NC300s socket. 

1. What Xtal do I need?  Is this is the output or INPUT Xtal FREQ?  What band does it output?

2. Will this work with the NC 300 tuned to the VHF band?  or will I tune the NC300 to say 80 meters and find the amecos output?

I have no experience with these, I do have an RME converter that will do 2 meter and 6 meter and has a built in VFO. It outputs on a fixed 80 meter Freq. 

C

[WQ9E]

Clark,

The manual is here: http://bama.edebris.com/manuals/ameco/cn50

You can crystal it to work with the calibrated NC-300 frequency.  Pay particular attention to the power wiring but the NC-300/303 will power it.

[Pete, WA2CWA]

There are three models: Ameco CN-50, CN-144, CN-220
They were sold with a variety of IF outputs. Crystal frequency obviously is important for your particular model. IF output sometimes was stamped somewhere on the outside chassis. Changing the IF output from what the box was designed for, also might require some part changing.

Yours looks like the 6 meter unit, CN-50. Most common ones were IF: 7-11 MHz, 14-18 MHz, or 28-30 MHz.

[WQ9E]

The CN series are simple to set up for any output frequency range but you may have to order the crystal needed.  The manual link I sent you covers the instructions and crystal frequency for the NC-300 converter range selection.

The CN series should serve you well.

[ke7trp]

No markings anywhere. I just studied the thing inside and out. I cant figure out if this will work or not.  What makes you think its the 6 meter unit?

Maybe I am just better off using the RME Converter. It has 2 meter and 6 meter bandswitched with a VFO and I know it works. I was trying to find a way to use the NC300's 2 meter band switch and VFO and to save space.

Thanks alot guys

C

[ke7trp]

After reading that manual again, I think this might be the 50.  The reason is that the two adjustments for the 50 apear to tbe the slug type in the photo and the 144 version shows to be a scew adjustment. 

This is not going to work for me then.  Also, The other thing I dont care for is that you need very exactly output freq xtals.. all the way down to .3333 ect.  That will be nearly impossible to get today.  One Xtal only gives you a small portion of the 2 meter band. 

Hmmm..  Anyone need this or dying to have this thing?   I can just stack the RME ontop of the NC300 and go on.

C

[WQ9E]

Clark,

Your unit is the 50 Mhz. version.  But you can still order a crystal today, the only difference is they are now a little more expensive (in reality the cost is pretty cheap adjusted for inflation from the 1960's).  One crystal does cover the entire 4 Mhz. range of the band, the range is only restricted if you try to use it setup for output on the BCB which isn't a good idea from the standpoint of image response.  But used with your NC-300 and the proper crystal it does cover the entire range and is MUCH more stable than the RME variable units (I have the ones that match both the RME-45 and the RME-4350 and neither is very stable).

[Pete, WA2CWA]

CN-50 is the only model that has a missing coil, i.e. the empty hole in front of the 6J6. Get a crystal to output to the 10 meter band and you'll have 50 to 52 MHz. The one I have outputs to 14 - 18 MHz which is great for 50.0 to 50.4 MHz on one of my amateur band only receivers.

[ke7trp]

That confirms it. Thanks guys. This is the 50.  There is no 6 meter am here.  none.  If someone wants thing badly, You can have it. Just cover shipping and packing. Otherwise, I will put it back in the store room and keep looking for the NC300 units or use the RME.

The new station I am setting up now includes:

Restrored and repainted Ranger 1,  Tbolt amp
NC300 that is cleaned and recapped.
6n2 that is redone with matching VFO.
RME 2 meter/6meter converter. 

Should be a neat setup.  Its going on one large table and will be used mainly on the 2 meter AM net and some 40 or 80 at night.

[Pete, WA2CWA]

Save or sell the nuvistors. People are looking for those things and they're great for low noise front ends. There's even a mod floating around using two of them for a SP-600 front end.

[WQ9E]

Clark,

Don't be too hasty in getting rid of that converter because:

a) 6 meters displays a lot of interesting types of propagation so you can operate AM during those openings.

b) It sure seems like there are a lot of vintage gear enthusiasts in AZ so encourage a little activity.  As soon as you give away the Ameco a vintage 6 meter AM group will spring up. 

6 is a very fun and interesting band.  I put together a very simple 2 element quad for a 6 meter contest last year and worked a number of stations in the southwest, Mexico, and the Caribbean area using an FT-625 barefoot.  I need to get my bigger gear ready for the Spring season.  I have a Clegg Zeus/Interceptor ready to go on AM along with a 6N2 Tbolt to provide more power for my lower power SSB/CW rigs.

 

[KM1H]

Dont use the 10M range. The NC-300/303 has a special 30-35 MHz converter band and the dial is calibrated for that output from the converter.  During E Skip 6M AM is loaded around 50.4

And dont worry about the crystal and all those 3's. Its no difference than a lot of zeroes and the manufacturers could care less. The converter has a tweaking trimmer to zero it in. The schematic sheel contains information for all popular IF's.

The National converters are junk; deaf and overload easy. Strictly good for bragging rights in the special cabinet as they are mighty scarce.

Carl

[WQ9E]

Now you have to go and run down the converters right after I finally got them Carl.   You mean these things aren't what I need to work moon bounce

Seriously, I don't expect them to be that great but I did want the console to go with my receiver and I got it with all 3 converters for $100.   I imagine the Tapetone units I picked up are probably much better.

[KM1H]

You did good there Roger, I guess I forgot you had them when I made that comment BUT its still the truth

The Tapetones still works well. I have several here and have run them on the HP NF meter and they beat out the typical SSB/CW ricebox by far on 6 and 2M. I also have the W2AZL 2M converter I built around 61 and it measures a nice 1.8dB NF which isnt to be sneezed at especially if using a tower mounted preamp.

Carl

[The Slab Bacon]

Ok, guys I cant see how that you would be that worried about the NF of the converter when the NC-300 has that noisy-assed 6BA7 for a first mixer.

I love everything else about thar RX except for the noisy first mixer. Did you find a way around it or what?? I have thought about making an adapto socket and trying something like a 6BY6 or maybe a plug in Pullen mixer circuit.

[KM1H]

A low NF converter with 20-25dB of gain will overcome the noise generators effect.

A Pullen or 7360 is the way to go

[KA2DZT]

You did good there Roger, I guess I forgot you had them when I made that comment BUT its still the truth

The Tapetones still works well. I have several here and have run them on the HP NF meter and they beat out the typical SSB/CW ricebox by far on 6 and 2M. I also have the W2AZL 2M converter I built around 61 and it measures a nice 1.8dB NF which isnt to be sneezed at especially if using a tower mounted preamp.

Carl

I have three HB W2AZL converters, not all exactly the same layout.  I didn't build these but I would like to fire them up to see how well they work.  I was going to post about them last night but didn't think anyone would know what I was talking about.

Fred

[Pete, WA2CWA]

You did good there Roger, I guess I forgot you had them when I made that comment BUT its still the truth

The Tapetones still works well. I have several here and have run them on the HP NF meter and they beat out the typical SSB/CW ricebox by far on 6 and 2M. I also have the W2AZL 2M converter I built around 61 and it measures a nice 1.8dB NF which isnt to be sneezed at especially if using a tower mounted preamp.

Carl

I have three HB W2AZL converters, not all exactly the same layout.  I didn't build these but I would like to fire them up to see how well they work.  I was going to post about them last night but didn't think anyone would know what I was talking about.

Fred

I have of three of them too including one that Carl built himself.
Here's a pretty one that VE6KQ built:

[WQ9E]

That's a nice shiny one Pete!

One of my over winter goals is to get more of the VHF stuff wired in and ready to go.  I now have 6 and 2 meter yagis ready to go up and my 6N2 Thunderbolt passed its bench test so now I need to set up a switch and cable arrangement so it will work with various rigs.

[W7POW]

If it needs a new home I could really use it.
Thx,
Chris

[W7POW]

Clark,
Is the converter still available for sale.  I meet weekly on Wednesdays at 4:00 pm here in Pac NW on 50.4 am and am currently using a RME converter on loan by a local ham.  I have been looking for a converter and would like to give back the RME asap.  Please PM me if it is still available.  Thanks and 73,
Chris.

[ke7trp]

Sure man.  Just PM me so you can call me. I have to ship a few things this week.  I am not going to use this thing and would like it to go to someone that actualy will enjoy it.

C

[KM1H]

Here is my W2AZL. Its not a shiny shelf queen unless I polish the brass cover but at least the silver plating inside still looks good.

Carl

[W7POW]

Carl...I like.  Really nice.

[Rob K2CU]

I have a CN-144 from long ago that still works. I believe i have two crystals for that unit, one to output 28-32 and the other for 14 to 18. I also have several other "converter" type crystals. These are the ones that end in .33333 or .66667, as they typically are tripled and then doubled, or not. I have ones that I used in 432MHZ converters that also end in .33333 or .66667. Most of the old converters used low side injection, but it really depended upon the image threat. You had to choose between aircraft or taxi cabs!
The IF output transformer was set up for easy changing to other frequencies, and usually had a loading resistor to broaden its output.

transmitter is a Tecraft 2 meter unit with built in AM modulator. we played with NBFM by tickling the crystal with a varicap diode connected to the mic amp with the 6AQ5s pulled.

Those were the days, long before repeaters.