Alinco DX-70TH Repair

 This is an Alinco DX-70TH hf rig I repaired for a local friend. He bought it at a hamfest as a "non-worker". Good receive, no transmit, VERY high idle current. I suspected finals... When I cracked it open, there were loose screws all over, main board loose, cables disconnected, etc. Oh well, sure enough, the n-channel FETs in the PA were hosed. 

I put everything back together, removed the FETs, and bypassed them with .01uF caps as a quick test. Nice QRP rig, did about 4 watts out. Beautiful signal, and proved the rest of the rig to be OK. I replaced the FETs, and it was a new rig. Here's a few pics...

Lafayette Comstat 35 Restoration

 This is a Lafayette Comstat 35 tube-type CB radio base station from about 1975. These were pretty popular and were high end 23 channel radios in their heyday. 

I saw this at a yard sale and couldn't help myself. It was lonely, dirty, and needed some love :-).

I gave this radio a full massage, replaced some tubes, capacitors, a few out of spec resistors, serviced all controls and switches, padded the pa output load trimmer to load correctly, replaced the internal speaker, gave It a full alignment, and added 2 more crystals to give it channel groups 26-35 (the AM channels). 

It has some character marks (scratches, etc), but overall looked very good for a 49 year old radio, see the photos. Power output is about 3 watts.  Receiver sensitivity is very good, .15uV @ 10dB. This is a very solid radio!

Icom IC-720 Repairs...

 This is an Icom IC-720 I bought in an estate sometime back. This was built around 1980. I don't have a clue what this poor radio went through, as it was in the basement and covered in mud. 

Expecting the worst, I started on the internals first (before wasting a lot of time cleaning). To my surprise. It was just the typical stuff...dirty switches, noisy controls, etc. The motorized band switch was seized up, but cleaning and lube fixed that. I replaced all of the 6vdc caps, a couple of larger electrolytics, and touched up the alignment. This old girl came to life and played like a new radio!

A bit of cleaning, and it went on to pull time in the shack of a new ham. Some of these old radios are real gems. Here's a video and a few pics...

Yaesu FT-890 Repairs

 This is a Yaesu FT-890 I repaired for a friend. It had a few problems... After transmitting a few minutes, the output would drop and become extremely distorted. There was a slight  error between rx and tx frequency. There was also intermittent noise in the receiver. 

I replaced a faulty ALC chip, repaired an intermittent cable between the PA and the exciter stage, replaced several caps around the audio multiplexer, aligned the rig, and modified the rig for increased power control in AM mode.