Heath HR-10 with a strange problem

Discussion in '"Boat Anchor" & Classic Equipment' started by WA9ZWA, Jul 9, 2019.

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  1. WA9ZWA

    WA9ZWA Ham Member QRZ Page


    I am working on a Heath HR-10 receiver. I have re-capped it and it's working. I have the manual and have peaked the IF up. The IF freq is 1681. There are 2 crystals in a crystal filer in the IF one at 1680 and the other at 1682. The IF peaked right up no problem. The 80 meter band had alignment problems. It was not hearing anything except a broadcast station, at a low level, across the entire band. I went through the alignment procedure as detailed in the manual. I now have it receiving signals in the 80 meter band. It seems pretty sensitive on 80. The rest of the bands were pretty good but I peaked them up as well. The AM broadcast station across the entire 80 meter band is still there. Last night I finally caught a station ID and it is WPRR in Grand Rapids, Michigan and it's on 1680 Khz. The HR-10 IF frequency. If the station was across the road or even a few miles away I might understand it getting into the IF...BUT it's nearly 300 miles away. I'm in Terre Haute, Indiana and it's in Grand Rapids Michigan. [​IMG] I only hear it on 80 meters. They run 10kw day and 1 kw night. I know when Heath was selling the HR-10 there were no broadcast stations on 1680. The FCC expanded the AM broadcast band back in the 90's and allowed some low powered stations on congested frequencies to migrate into the expansion. There are only 6 or 7 stations on 1680 across the country.
    Somehow the RF is getting into the IF. Any ideas how this is happening? It's got me scratching my head. [​IMG]

    Thanks in advance!

    Barry WA9ZWA
  2. WR2E

    WR2E Ham Member QRZ Page

    If the signal is coming in via the antenna connection you might be able to install a series tuned trap at 1680 to get rid of it.
    KP4SX and N2EY like this.
  3. KE4OH

    KE4OH Ham Member QRZ Page

    What WR2E said. A trap, high-pass filter, something to kill the 1680 AM signal.

    I have an HR-10. It's not a fabulous radio, but they are a cheap and easy way to get started with boatanchor radios. I use mine on CW and have thousands of QSOs in the log with it. After you lock down the signal bleed-through, look into sticking a VR tube in there to stabilize the oscillator voltages. Makes a huge difference.
  4. N2EY

    N2EY Premium Subscriber QRZ Page

    The problem is that the front-end selectivity on 80 meters isn't enough to stop the 1680 kHz signal.

    A series trap from the antenna input to ground, tuned for 1680 kHz, is one solution.


    Give the HR-10 a good hard lookin'-at. In particular, check for cold solder joints, loose screws and hardware, missing parts, wrong parts, and similar things. Assume nothing. Here's why:

    With radios that were built from kits, there's no guarantee that the thing was actually built correctly. Despite Heathkit's excellent step-by-step assembly instructions, people made mistakes - particularly inexperienced builders not used to reading color codes and such. Finding an assembly mistake from half a century ago is not unusual at all. Many mistakes would not prevent the radio from sort-of working, and with nothing to compare it to, the builder could easily think "that's just how it works".

    I've known hams who simply would not own a kit rig, no matter what, because of this issue.

    73 de Jim, N2EY
  5. W8TMT

    W8TMT Ham Member QRZ Page

    Ironic that it's coming from Michigan!
    AF7XT and W2VW like this.

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