Restoration Project #2

Full restoration of a 1963 Heathkit HR-10B 80 to 10 meter receiver

 

Current restoration status

as of 12/09/2017

 

Video link showing the mixer input to the AF output successful test. The meter indicates FS after slight IF can adjustment.

Heathkit HR10B Restoration mixer input to audio output RF and AF test

Video link showing 3.5Mhz 80 meter RF signal from my Heathkit IG-102 SigGen fed to the antenna coax cable and the S meter pegged fully to the right. The BFO oscillator needs adjusting but for now the HR-10B receiver is working!!

Restored HR10B is working

Video link showing the HR-10 on 75 meter AM.  I had to tune the receiver using my finger as the dial cord is not installed. The top cover is just slid onto the receiver for now.

Restored HR10B Ham Band Receiver

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Before restoration

The five pictures show the physical condition of the HR-10B when it arrived from the seller.The seller did not cause the rust but rather a long ago previous owner did. The HRA-10-1 100Khz Calibrator was not included. I have since purchased a HRA-10-1 100Khz calibrator without the crystal and 6BA6 vacuum tube. I have the crystal and tube in stock. Also note the rust on the front panel, the chassis, the audio and power transformers. I missed it but the dial pointer is missing. I found a non-Heathkit dial pointer that appears to be a suitable replacement but it is not Red. In additional to the rust and corrosion the long ago previous owner scratched his name, address, and SSN on the receiver’s chassis in 3 places. The top cover has stains and some rust spots so it ill need attention, most likely repainting.

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Front panel restoration

Before stripping the front panel, I made measurements where the dark Green dial trim and control area paint is located on the front panel. I first sanded the panel and applied a coat of Rustolium Winter Gray over the entire panel. I then masked off the control area and applied a coat of Rustolium Dark Green paint which immediately pitted in a small area around the volume and RF gain controls. I decided to strip the panel of all original paint, sand the panel, then apply a coat of Gray primer. Using the measurements, I masked off the panel exposing only the control area, and applied a coat of Rustolium Dark Green paint, success, no pitting. I further masked off the dial opening and applied the Dark Green trim. Last, I masked off the dial trim and applied a coat of Rustolium Winter Gray to make the dial trim look original. I’m not a professional painter but I must say the panel looks very good!!! When painting, mask sure you wait a minimum of 36 hours for the paint to completely dry!!!

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Chassis Restoration

Pictures of the chassis after complete disassembly of the receiver. The left picture shows the chassis before any cleaning took place. The middle picture shows the chassis after attempting to clean the chassis using Simple Green. Not much improvement. The right picture shows the chassis after sanding and applying a coat of Rustolium Metallic Nickel paint. Now the chassis looks great.

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Reassembly

Assembly of the HR-10B using a complete HR-10B assembly manual from w7fg.com. New tube sockets replaced the original sockets. The power transformer was cleaned of rust using my Dremel tool and a wire brush attachment. A new triple capacitor can from Hayseedhamfest, and the wiring harness was cleaned up and reused. The original RG58 coax cable was replaced with smaller RG174 coax. The receiver’s front end assembly wiring was, after removing during disassembly, too short so new Yellow wires and resistors were installed. The front end assembly was installed then connected to the RF amp and local oscillator. The RG-174 coax cables were connected. The 4 original CAL RESET, ANT TRIM, BFO TUNE, and Main Tuning, were cleaned and the bearings were lubricated with DeoXit L260ap conductive grease. The pots were cleaned with DeoXit F5 Fader cleaner/lubricant and all 5 slide switches were cleaned with DeoXit D5. Generous amounts of canned air was used to remove cleaner residue. The band switch wafers were cleaned with DeoXit D5 and canned air removed all cleaner residue.

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Initial power up and operational test

Initial power up test were conducted successfully. IF test was successful but the RF test failed due to 2 wiring errors, one in the RF stage and one in the local oscillator stage. Fixed the wiring errors and retest was successful. The optional HRA-10-1 100Khz calibrator was not included in the receiver purchase. I found one on eBay, that didn’t have the 100Khz crystal nor the 6BA6 tube. I cleaned up the calibrator’s chassis, masked off the trimmer, capacitor, tube and crystal sockets, then painted the calibrator chassis Rustolium Metallic Satin Nickel to match the receiver chassis. After the paint dried I installed the tube and crystal in their sockets then plugged the calibrator into the rear octal socket and the calibrator tested successful.

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Decals

The top left picture shows the HRA-10-1 calibrator with a restored chassis and new decals. The top middle picture shows the rear panel with new decals and the original metal tag. The top right picture shows the tube decal labels. I had problems making White decals for the Dark Green control area so I had to replace the original panel with an HR-10B panel I purchased from Tom at Hayseedhamfest.com. The replacement panel would not fit flush on the front of the chassis. The problem turned out to be the lower edge of the dial plexiglass was positioned too far down behind the front panel. This prevented the front panel from mounting flush to the chassis’s front apron. This also prevented the 3 slide switches from sliding left and right as the panel would fit “tilted” causing the switch slides knobs to rub against the bottom opening of each switch. Once the dial was moved up, the panel fit flush against the chassis and the slide switches moved freely left and right. The threaded shaft on the AF Gain pot, with the ground washer/lug behind the front panel, would prevent the threaded shaft protruding sufficiently through the front panel, to allow the nuts to be attached. I removed the washer/ground tab from the pot, made a wire ground connection from the pot terminal to a nearby ground lug, and the pot fit perfectly through the front panel and the nut was easily attached, securing the pot the the front panel. This made the top cover fit perfectly as it should.