====== 1254 Review by Paul Bigelow ======
**From the Ten-Tec Reflector April 1, 1998**

I have built the 1254 receiver and it is a nice little unit.  A real joy to build, use and tune around.  I haven't had this much fun in ages!

**Features:**

  - Great sensitivity (compared against the NRD-525) and the sensitivity is relatively consistent across the 100kc-30000kc receiving range.
  - Good selectivity (for a 4kc filter)
  - Reasonably stable
  - Excellent quality boards
  - Easy to service (except for removing parts from the plated through holes)
  - Convenient to use
  - Informative, relatively easy to follow instructions

**Suggested change:**

Mount an RCA jack with a nylon washer on the outside to the back panel to reduce stress on the board.

**Quirks noted and possible remedies:**

  * Lots of birdies and display induced signals on the lower half of the AM broadcast band.
    *Remedy:  Have attempted to shield out the multiplexing emissions by spray painting a graphite EMI/RF shield to the inside of the front cover.  It helped a little bit.
  * Reduced sensitivity on the lower half of the AM broadcast band.
    *Remedy: Put a jumper across R72, eliminating that input filter.
  * FM intermod from strong FM stations.  Just add 90  (2* 1st IF) to the received frequency to detetmine offending frequency.
    *Remedy: Have tried with some success (but none totally satisfactory):
      * Snap-on RF choke on power cable
      * Soldered on a shield on trace side of the board around the 1st Mixer section.
      * Incorporated FM trap (from Radio Shack) in the antenna lead.
  * The rotary Encoder loosens up with use causing the frequencies to jump around (sometimes) when tuning from one step to another.
    * Possible Remedy (have not tried yet): Sandwiching a large, black, felt washer between the tuning knob and the tuning knob recess to reduce play.
  * Hum from the power supply.
    * Possible Remedy  (have not tried yet): Install a 15V IC regulator in the power supply.
  * Deafening thump upon turning on the 1254 when using headphones.  REALLY LOUD.
    * Remedy: None yet although I suspect a large capactior may resolve this one.
  * A little bit of "thumping" due to slow synthesizer lock.  Not too bad, really, considering the price.

Paul