07-09-2020, 03:11 PM
...But only minor.
Over the holiday weekend, I made some use of my Yaesu FRG8800 https://www.eham.net/reviews/view-product?id=807
When we travel up to Northern Cal, I like to take a different set form the collection each time, as I can spend a bit of time listening while up there, and spend some quality time with the radios in turn.
Anyway, on AM, I noticed that the tuning band pass is a little shifted, meaning that one has to go a kc or so lower than the channel frequency to get the best audio. Now I know the set 's oscillators are aligned, as tuning in on SSB gives zero beat when the dial reads the station frequency. It looks like one of the crystal filters has drifted off center frequency with age - a bit like not having the IF transformers properly peaked, but the crystals are not adjustable... Since it is really noticeable in the wide bandwidth setting, this points the finger at a specific filter. Interestingly enough, I had a very similar but more severe issue with another radio, and the filter appears to be from the same series. Finding exact replacements is hard, but on the other set, I was able to make a small piece of perf-board to mount an electrically equivalent filter, and connect this to the main board with very short wire legs. The harder work will be to extract the main board from the radio - I already have a filter that will work. Before starting, I'll "jump" the filter with a small cap, which should confirm that it is the culprit.
The FRG8800 is a nice set, and I got this one as a pretty good deal a few years ago. In particular, it has good audio from a front facing speaker. Last weekend it was receiving Radio New Zealand (13,840 kHz) very happily on a small loop of wire strung around the living room window frame.
I tend to think of this 80's-90's era of radios as modern, but they are rapidly becoming classics. Restoration comes with some new challenges compared to our "tube" favourites, but they can be kept in service to good purpose. Nothing like them is made nowadays.
Cheers
Ed
Over the holiday weekend, I made some use of my Yaesu FRG8800 https://www.eham.net/reviews/view-product?id=807
When we travel up to Northern Cal, I like to take a different set form the collection each time, as I can spend a bit of time listening while up there, and spend some quality time with the radios in turn.
Anyway, on AM, I noticed that the tuning band pass is a little shifted, meaning that one has to go a kc or so lower than the channel frequency to get the best audio. Now I know the set 's oscillators are aligned, as tuning in on SSB gives zero beat when the dial reads the station frequency. It looks like one of the crystal filters has drifted off center frequency with age - a bit like not having the IF transformers properly peaked, but the crystals are not adjustable... Since it is really noticeable in the wide bandwidth setting, this points the finger at a specific filter. Interestingly enough, I had a very similar but more severe issue with another radio, and the filter appears to be from the same series. Finding exact replacements is hard, but on the other set, I was able to make a small piece of perf-board to mount an electrically equivalent filter, and connect this to the main board with very short wire legs. The harder work will be to extract the main board from the radio - I already have a filter that will work. Before starting, I'll "jump" the filter with a small cap, which should confirm that it is the culprit.
The FRG8800 is a nice set, and I got this one as a pretty good deal a few years ago. In particular, it has good audio from a front facing speaker. Last weekend it was receiving Radio New Zealand (13,840 kHz) very happily on a small loop of wire strung around the living room window frame.
I tend to think of this 80's-90's era of radios as modern, but they are rapidly becoming classics. Restoration comes with some new challenges compared to our "tube" favourites, but they can be kept in service to good purpose. Nothing like them is made nowadays.
Cheers
Ed
I don't hold with furniture that talks.
