New Heathkit station

[VE3LYX]

Last week I aquired a DX60B. It was in pretty nice shape except for two cracked knobs (which I shall find and replace) At first I couldnt get it to work on AM but found the centre mic contact worn to the point of not touching. A minor repair and a hunt through the shack turned up two useable microphones. The only rocks I have for 40M were 7145 and 7050. For AM 7145 seemed best. After some last minute searching and antenna repair I made the frst contact with this rig with Ve6pg thanks to his patience and perseverence. Today I dug out an old Mohichan Receiver I had had for years.  The Rf gain pot is siezed but I did get it up and running. Calibration is surprisingly right on so tomorrow or someday soon I am hoping to make an all Heathkit Qso from my QTH. I thought about a VFO but you know most of the AM activtiy is on very specific freq's so I ordered the required rocks . The Antenna for the Mohichan sticks up to far to put it in my shelf so I will have to temporaily remove it. tis kinda fun having a vintage Heathkit station. Not something I ever aspired to but fun just the same.
Don VE3LYX

[K7EDL]

Nice thing about heathkit, you can have fun without a lot of money. And they were made to be worked on.

Enjoy your new rig, I hope to start on a heathkit station soon.

Eric

[W3GMS]

Don,
Congratulations on getting your DX-60 on the air!  It was my first rig as a novice back in 1966.  I still have one along with the matching HR-10 receiver and HG 10 VFO.  The HR-10 receiver is nothing to write home about but I hope to do some circuit re-design to make it a little bit more road worthy. 

I just helped Bill, W2DGB restore his newly acquired DX-60B and I had the pleasure of working him the other day on the air with it.  He used a D-104 mic and it sounded very good.  Not Hi Fi, but it was kind of neat to hear that vintage DX-60 sound.  I plan on ultimately modifying mine per Steve's, WA1QIX's audio mods which make the rig sound absolutely wonderful. 

Enjoy....
Joe, GMS

[Knightt150]

There are some modifications for the DX60 series that make that transmitter sound as good as any COLLINS. I know after 51 years of tuning the ham bands I have heard them all.

I would like to make the same modifications to my two screen modulated T150's, but I have not found a circuit that someone has tried and works that good.

If you hear of one let me know.

John W9BFO

[VE3LYX]

Joe, What would you say is the biggest thing you would improve on the HR10 rcvr?I am curious as I seriously considered finding one.
Don VE3LYX

[W3GMS]

Hi Don,

The first thing I want to do with mine is to build a high Q wave trap resonated at the IF frequency and put it on the front end of the receiver.  With our expanded AM broadcast band the HR-10's IF is very prone to pick up broadcast stations near the IF frequency.  A couple of years ago when I was using the HR-10 on Straight Key Night I was copying CW with Spanish a speaking BC station in the background.  So rather than move the IF frequency, I think I can just trap the IF frequency out right at the first stage.  Someone suggested an inductor wound on a loop stick would work well and I concur. 

The AVC is not really good on the HR-10.  It appears that the dynamic range of the AVC loop just does not have good dynamic range which may involve some better tube selections within the receiver.  The time constant could be a bit more optimized as well. 

This is not so much of an AM issue, but on CW I want to cascade two of the same frequency filters rather than using the two staggered filters parallel to each other.  For AM this is fine but have a switch position to cascade two filters of the same frequency would make it much more selective on CW. 

The audio and detector circuits need some work as well. 

My goal is not to make it a great receiver, but just a bit better than it currently is.  I want to sit down with it on the bench and characterize its current design by taking various measurements.  Once the numbers are known then decide what and where I want to make performance enhancements.  Then the design process will start. 

Joe, W3GMS   

[gerry_w1id]

The HR-10 has a number of shortcomings which in my opinion removes it from consideration for any kind of serious amateur use. Selectivity, stability, as well as poor sensitivity on 15 & 10 are real problems. CW reception is mediocre due to lack of a product detector and the previously mentioned shortcomings. However I have had a lot of fun experimenting with mine. 73 Magazine published an article in November 1972 describing a modification to add AF derived AGC for CW/SSB and a few other minor tweeks to improve BFO injection and stability. I've done these mods and added another IF filter stage by using the components from a parts rig. That makes it a lot more useful on CW. The next thing I will work on is the BFO and maybe even adding a product detector. I noticed last December that the BFO frequency gets pulled a little with maximum signal. I am thinking of solid-stating the BFO with a FET and adding a real product detector. The power transformer is getting a little hot so I'll put in a transformer from an SB-300. Ultimately I really won't have a real HR-10 but who cares? This is not a collectible rarity and the stock rig is a real POS. I just want a decent matching receiver for my DX-60 which by the way is a great little transmitter. I've had probably 4 of them over the years, including one I bought at the old Heathkit store in Newton, MA. Unfortunately I sold that one many years ago. But boy what a trip that was: going to the Heathkit store after school to pick up a kit!

[Tom W2ILA]

I run the DX60B, VFO, HR10B combo when conditions are favorable.  Since operation here does not fall into the "serious amateur" class the combo definately is not considered a POS.  All contacts have been a lot of fun, the transmitter gets good reports (slight mods done long ago) and the HR10B always reminds me of a Christmas decades ago.   
An antenna tuner in front of the HR10B will solve the AMBCB problems but a hi-pass filter is a worthwhile project as previously mentioned.  PTT is also worthwhile because the mode/transmit switch is a weak link in the DX60B.
There are plenty of HG10B VFO's at the fests at reasonable prices too.
Have fun with that setup.

TM